Generating $70,000 Per Month Through Organic Growth Methods

Hello! Tell us about yourself and what are you working on?

Hello! I'm Romain Vialard, a self-made programmer from Paris, France, and the creator of Yet Another Mail Merge (YAMM) — an email marketing and email personalization tool.

Thanks to our users, we are the top mail merge add-on for Gmail with over 860,000 users, and we're now making $70,000/month.

Yet Another Mail Merge

How'd you come up with the idea for Yet Another Mail Merge?

In 2010, around the same time when Google announced Google Apps Script, I started my internship with Valeo, one of the first large businesses to have "gone Google". I then interned with Revevol, Europe's largest G Suite Reseller of Google.

In those days business interns were expected to write macros in Microsoft Excel to automate tedious tasks and processes. As I was working for companies which were migrating to Google productivity tools (Gmail, Google Drive, and Google Docs) I picked Google Apps Script to write macros for Google spreadsheets, which was the right tool for the job. With it, I created many useful automation scripts that increased productivity.

One script that I created simplified internal training registrations. I integrated Google Calendar and Google Spreadsheets with Google Form and automated the process. At the end of every registration, the tool would send registration confirmation emails to the registrants with appropriate training details. In other words, the tool sent transactional emails with personalized information. Et Voila! That's the seed for today's YAMM.

What went into building the initial product?

The first version of Yet Another Mail Merge was built over a Google Apps Script code sample provided by Google themselves at that time. My company was working on a mail merge requirement for a client, and the people on the project chose Google Sites as the mail merge template source. For me, it appeared to be a rather cumbersome solution.

Around the same moment, Google released a new connector to Gmail. It gave me the idea to have the mail merge template in Gmail as a draft. So I created a script, named it "Yet Another Mail Merge", and shared it on Google's App Script gallery to be used by other developers and users.

Some people at Google liked the idea, and a few weeks after publishing YAMM, I co-authored a guest post where I presented it as one of several ways to do the mail merge with Google Apps Script.

Build small, try, and fail. You can worry about more challenges once you get more users.


The first version was more of a minimum viable product (MVP) that served with features that were just sufficient to satisfy early users. It took some of my evenings and extra hours to get it into shape. I did this for no money. The Google App Script gallery, where I first shared my script with other developers, was a repository of scripts. People could import a copy of a script source code into their spreadsheet and use it as their own.

New users continued to adopt the script. With this added feedback I kept refining my solution. At the same time, Google Apps Script itself was also becoming better and better, giving me new tools to improve YAMM.

How have you attracted users and grown Yet Another Mail Merge?

In March 2014, Google replaced its App Script Gallery with its Add-on store, making it way easier for users to install a script and way easier for developers to maintain them. YAMM was one of the first 50 add-ons to have launched on the add-on store. And it was a success! This new marketplace attracted many users, and YAMM benefited a lot from it.

Yet Another Mail Merge on Product Hunt

To this day, YAMM has gotten all its 860,000+ users from visitors to the add-on store. Our growth is 100% organic. Our position as the top mail merge add-on and the positive reputation we've gained from our loyal customers have attracted more new users for us.

Additionally, our referral program and the recent Product Hunt launch continue to bring us new traffic. With more than 100,000 monthly active users and 23 million emails sent every month, YAMM's new installations keep growing.

What's your business model, and how have you grown your revenue?

We offer YAMM as a freemium product. The script is free for anybody with a Gmail account to merge up to 50 emails per day. Our premium plans offer users a higher email quota (400 emails a day for Gmail users and 1,500 for G Suite users) at an affordable price. Our revenue comes from annual subscriptions and renewals.

Our profit margins are very high, as we don't spend any money on email servers (we use the Gmail API to send the emails) and don't pay commission to sell on the Google add-on store.

Until September 2014, YAMM was available for free on the new Google add-on store. But success in this marketplace meant that I was spending more and more of my free time on support and improvements. While I was answering support requests during my vacations, I decided it was time to monetize. Plus, it seemed like a fun challenge. :)

As YAMM is a tool to send batch emails it made more sense for me to monetize based on quota limits rather than on premium features. I was already collecting usage stats in Google Analytics: In July 2014, my users were sending more than 300k emails every day. 97% of them were sending a little fewer than 200 emails in one batch.

I decided to target the remaining 3% (the heavy users) and reduced their quota in the free version from up to 1,500 (the limit set by Google) to 200 recipients per day. I used PayPal to quickly launch a paying plan for those who wanted to send more emails than that. And it worked! Of course, some users left to find free alternatives but many were happy with the product and were okay with paying.

After this successful switch from a 100% free product to a freemium one, I did (and I'm still doing!) some fine tuning, increasing the price, or lowering the free quota to generate the biggest revenue possible while continuing to grow our user base. To this end, I knew I had to find a solution to keep some users who aren't so willing to pay. So I decided to simply copy Dropbox and went for an in-app referral program. Once again, the add-on usage tracked using Google Analytics was helpful for me to pick the right quota to give for each referral.

To this day, our customers find YAMM very affordable for the value it provides for them. And we allow YAMM premium plans to be purchased directly on our site via PayPal or credit card.

Yet Another Mail Merge premium plans

What are your goals for the future?

Growth! YAMM users are very satisfied with the product as it is today. So my primary focus is to let more new users discover and fall in love with it.

With more than 100,000 monthly active users and 23 million emails sent every month, YAMM's new installations keep growing.


In the coming months I want to see YAMM become the top installed Google Sheets add-on in the add-on store. (It is now the second.) The next target is to become the first Google Sheets add-on with one million installs.

If you had to start over, what would you do differently?

I sold one of my scripts, Gmail Meter — a tool that sends a monthly report of your email usage & behavior stats — for some quick cash.

At the time I was super happy that someone was willing to give me money for it. But maybe it wasn't a good idea, especially to sell it for a low price, while I could have totally monetized the tool for more over time.

Have you found anything particularly helpful or advantageous?

Yes. Mostly Googlers and Google!

From the day I fell in deep love with Google Apps Script I had been advocating the technology and was spreading the good word about it on the product forums. That's when the first product manager of Google Apps Script contacted me to know more about me and how I was using Google Apps Script at my internship.

Later he sent me a few goodies and a handwritten postcard, thanking me for my contributions. I was very touched by his gesture, and they kept me motivated for so long. He was the one who invited me to write the first guest post on Google Apps Script.

When the add-on store was launched, every add-on that was added to it initially got reviewed and tested thoroughly for its user experience and UI improvement. This meant that Google ensured the quality of each add-on before making it available to its audience. The person in charge of those reviews at that time gave me great feedback on how to improve my products.

Google is quite good at recognizing and rewarding fans and people who are advocating its products. And this kind of close relationships with Googlers in my early days made proved to be resourceful.

I am a Google Developer Expert and also a Google Top Contributor. Thanks to these statuses, I get early access to Google technology and Google's product teams.

What's your advice for indie hackers who are just starting out?

Try to create an add-on! There's a big demand and not so many offers. There are many more use cases that could be solved with add-ons, especially over Google Sheets (since for decades now people have used spreadsheets to build applications, and add-ons are making the process way better).

I've been able to run a successful business based on this marketplace. There are still so many opportunities and Google's add-on store is big enough for many more developers and companies to build new stuff:

  • It's an active marketplace with many users looking out for products that can suit their Google tech stack.
  • Google Apps Script is quite easy to use. It doesn't require great tech skills to create your first script.
  • You can build small, try, and fail. You can worry about more challenges once you get more users.

In the end, an add-on store with more new and interesting products will not only be beneficial for the Google users but can also bring more and more potential buyers to all add-ons available, including my own.

Where can we go to learn more?

You can try YAMM for a special 3-month free premium license for Indie Hackers!

My other products are:

  • Awesome Table: A data visualization tool with nice views (cards, maps, table, Gantt view) for Google Spreadsheet data.

  • Form Publisher: A data merge tool that turns Google form submission data into documents with predefined layouts (possible formats Google Docs, Sheets, Slides, and PDF).

I make blog posts on Google's technology and about my products on my G+ page.

Thanks for readign. Please leave your comments for me. You are most welcome to use me as a sounding board if you want to create your first add-on for Google add-on store.

Romain Vialard , Creator of Yet Another Mail Merge

Want to build your own business like Yet Another Mail Merge?

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  1. 4

    I just have to say Thanks to Romain for this awesome tool. We used it a ton in the early stages of our startup. The free limits are super generous and you get full access to all features. The referral program is great as well, and allows you to expand your quota.
    It's such an easy product to use, I highly recommend it. It's one of those products that is so useful you don't mind paying the premium price. It's definitely worth it.

    Just discovered Form Publisher from this interview and the credibility Romain built with YAMM tells me Form Publisher is going to be great. We are already brainstorming ideas of how to use it in our startup. It will be able to help us test some features out quickly without having to build it ourselves.

    1. 1

      Thanks :)

      1. 1

        Agreed! Thanks Romain. You've also helped us and always had amazing support!

  2. 3

    This is awesome. The main reason that I use Streak is because of their mail merge feature. Mail merge is really killer. If Streak gets annoying, I will switch to YAMM!

  3. 3

    Great info, thanks for sharing. Do you see any major changes to your market coming down the pipe?

    1. 2

      The mail merge use case represents the main category among all add-ons available for Google Sheets. We have seen more and more competitors entering the market but we continue to attract more users faster than the others.
      Real major changes can mostly come from Google, if they introduce new features in Gmail, decide to change their APIs,... But up till now, all changes coming from Google have mostly been positive for us :)

  4. 3

    Great article!

    What is the best way to figure out what types of add-on's have demand?

    Where should one start when trying to figure out what use cases (with high demand) could be solved with an add-on?


    1. 4

      You can start by trying to solve some problems users are having with the Google Docs editors (documents, spreadsheets, presentations, forms).
      Example of that are add-ons like one to remove duplicates in a spreadsheet, or automatically generate a table of content in a document.
      You can check Google Help forums to see which features people are asking for. Of course, those basic needs also have more chances to be answered by Google directly at some point.

      Google spreadsheets are also very useful to import / export data from another source so you could also try to build a connector with another popular SaaS application.

      1. 1

        Makes sense. Thank you!

      2. 1

        one to remove duplicates in a spreadsheet

        That's been solved by Power Tools ( It's another great add on that I recommend. We had a ton of customer data with random formatting and Power Tools really helped up fix it all up.

  5. 2

    Wow, this could not have come at a better time for me. Thank you so much Romain. The apps script tracking post may have just saved my life.

    I pushed my add-on to the store in October, and have had pretty solid initial sign-ups (~6,600) but my conversion rates really stink. I need to do some testing, but was unable to do so until I could get a good tracking solution implemented.

    I'm going to go over this article many more times, but thank you again for the advice!

  6. 2

    Wow! Super inspiring. I am just starting out and really love learning the genesis and lessons learnt from people like you. Thank you for sharing your story Romain.

  7. 2

    Hey Romain, many thanks for sharing your story here on IH. Inspired by your "I have started a little expirement..." article from 2014 as well as other data connection add-ons, I developed a Sheets add-on with my team over the last months. After a couple of iterations with the indeed helpful Google docs review team, we just received the following message today:
    "Your add-on has been reviewed and is now approved for public use! AppStoreMetrix will now appear in the Google Docs
    Add-ons store. "
    Our first target group is analysts working with mobile app reports. We have some early validation with a couple of dozen users from the private beta and will now iterate further as well as try to monetize obviously.
    I totally agree with you that the add-on store has a lot of potential. It is not that crowded yet and offers such a great opportunity to spice up Google Docs with all kinds of services from the web. I have already some ideas... but first I need to concentrate on the just launched one. :)

    1. 1

      Congrats! And good idea, I know a few people who will definitely be interested by this add-on :)

  8. 2

    Great interview. What I don't understand is the difference between Gsuite Marketplace and the Add-on store. It seems YAMM is in both, and in the interview you talk about the Add-on store. Can you help?

    1. 8

      Great question!

      The add-on stores only include solutions tightly integrated in the Google Docs editors UI (documents, spreadsheets, slides, forms), meaning we can display information in a dialog box or a sidebar within Google Sheets for example. Most add-ons aren't available as stand alone web apps, they only live in Google Docs editors.
      People can also install add-ons without leaving the editor (eg: they open a spreadsheet, click on the add-on menu, select and install an add-on, then start to use it without ever opening a new window).
      The add-on stores are easy to find and many users are installing add-ons, so it's a very good marketplace on which to launch a new product.

      The GSuite Marketplace mostly list web apps compatible with Google authentication and somehow integrated in G Suite (meaning they can connect to Gmail or Google Drive, but it's not mandatory).

      YAMM is available on both marketplaces (add-on store & GSuite Marketplace) because some admins of G Suite domains are forbidding their users to install add-ons by themselves. As my add-on is available on the G Suite Marketplace, an admin can forbid people to install add-ons but at the same time decide to install YAMM on his domain (making it either available to everyone or to a specific population on his domain).

      You can see that the number of users for YAMM is different on both marketplaces:

      I prefer to rely on the add-on store count, which is incremented / decremented every time a single user install / uninstall the add-on on his Google account.
      The G Suite Marketplace count is different: when an admin install an app for all users on his domain, all those users will be added to the count. So, if an admin of a big EDU domain install YAMM for everyone, my number of users on the G Suite Marketplace will get a big jump, even if nobody on the domain ends up using.

      It's possible with Apps Script to detect if an active user of your add-on has installed from the add-on store or got access via an installation from the G Suite Marketplace.
      Nearly all our active users have installed via the add-on store, not the G Suite Marketplace, even if our number of users on the G Suite Marketplace is bigger.

      1. 1

        Hi Romain, thank you for the detailed explanation. That makes sense.
        I tried to google "g suite marketplace vs add-on store" (and variations), but got no sensible results.
        Good luck!

  9. 2

    Hey! Thanks for the interview.

    How do you implement a paid plan for an extension like this? Does the extension ping your server to verify the subscription?

    1. 1

      Yes. We are using Paypal to process paiements. Through its IPN service, Paypal can send subscription notifications to your web service so you can record the transaction in your database.
      I've written an article containing a small code sample of that:

      We are using the Firebase Realtime Database service from Google as our main database, where we are storing user profiles, including subscriptions.

  10. 1

    So mail merge is basically mass mailing? Gmail doesn't limit the number of emails you can send in a certain period or is that the secret sauce of YAMM?

  11. 1

    @Romain_Vialard. Great idea and product. I remember reading your post about YAMM 4-5 years ago.

    It was very inspirational for me at this time and it still is. The link is still in my bookmarks :). I always think about developing an grammar checker or some similar utility add-on for MS Word.

    Now there is Office 365 and and add-on development for Office is easier and flexible.

    I wonder if you have considered adapting YAMM to Office 365 as well? I wonder if Office 365 add-on store is a profitable market.


    1. 1

      I'm wondering as well :)
      So far I haven't really investigated that so I don't know how the ecosystem of Office 365 add-ons work and if it's any good.

  12. 1

    Thanks @Romain_Vialard, I just had the add-on reviewed yesterday, so it took almost a week. Thanks for your reply!

  13. 1

    Thanks a lot for your post, very interesting stuff. Do you know how long it takes for an add-on to be approved? I tried publishing one 4 days ago and it still shows as "pending review", is this normal? Thanks!

    1. 1

      Hi, it can take up to 2 weeks for the first review to happen.

  14. 1

    @Romain_Vialard How do you capture lead information to your add-in? For example, if someone sees this article and goes to the chrome store to download YAMM, how do you capture them coming from

    1. 1

      That's quite hard to do as we don't have any real control on the installation page (powered by the Chrome Web Store and controlled by Google).

      But we found a way, through a proxy / redirection.
      For example, if we put a link to install YAMM on, this link will direct users to a web service we own, save info in the users's web browser local storage then automatically redirect user to the Chrome Web Store.
      Once the installation is done, YAMM automatically checks if our web service has stored info on the web browser and, if so, store the info (the fact that this user is coming from in the new user profile in our database .

      I'll try to post an article about that, with some code snippets to help other developers do something similar.

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