I Used to Get Distracted by Email. So I Built a Tool to Stay Focused.

Hello! What's your background, and what are you working on?

Hi! I'm Peter Hartree, and I'm the developer of Inbox When Ready, a Chrome extension for Gmail which helps people cultivate a better email workflow.

I made my first website when I was 12 and worked as a freelance web developer during my teens. I gained a bachelor's degree in philosophy, then worked as a freelance contractor for a few years. I now work (nearly) full time in a remote role at 80,000 Hours, a nonprofit which helps people have a big positive social impact with their careers.

Inbox When Ready started out as a "scratch my own itch" weekend project. Two years on, the extension has 2,000 weekly active users and revenue of $1.2K/month. People who find the extension a good fit reclaim 30-60 minutes of focused work each week they use it.

What motivated you to get started with Inbox When Ready?

During my undergrad I read about the extended mind thesis, which encourages us to think of computers as extensions of our biological minds. Since then, I've thought quite a bit about "extended mind design" — I think this is a useful frame for thinking about many techniques and tools commonly tagged as "productivity advice", "lifehacking", or "metaskills".

A key function of your extended mind is to help you allocate your attention effectively. Our daily attention environment is surprisingly hostile by default, because a lot of actors have strong incentives to misdirect our attention. Recognizing this, I began observing how my attention shifts during the day and taking measures to make my attention environment more amenable to what Cal Newport calls "Deep Work".

One morning I was doing some programming and I needed to ask my client a question. I opened Gmail with the intention of emailing the client, but my attention was immediately derailed by some new messages in my inbox. When I remembered my original intention (perhaps 30 minutes later), I realized that Gmail would be much less of an attentional liability for me if only my inbox were hidden by default.

I hacked a Chrome extension to implement this functionality the following day. I used it for a few weeks and found it was a big win for my focus. I went from seeing my inbox 10-20 times a day unintentionally to just once or twice intentionally. I published the extension on the Chrome Web Store, shared it with a couple of friends, then went back to my day job. That was October 2015.

What went into building the initial product?

In the months that followed I began receiving a trickle of thank you's, feature requests, and bug reports. In spring 2016 I realised that the extension had accumulated ~25 weekly active users and a handful of positive reviews from complete strangers.

So I decided to block out 10 days in the summer to work on the extension some more. My plan was to fix some bugs, setup basic analytics, make a marketing page, and do some user research. Fundamentally, I wanted to get a better sense of whether this could be something that a lot of people would want.

Over the summer I emailed and Skyped with several dozen people who said they loved the extension. The early analytics data looked promising — about 30% of people who tried the extension were still using it after two weeks, and a lot of users were keeping their inboxes hidden for several hours each day. This made me think I should keep working on the project, so I blocked out another 30 days during the autumn to focus on product development (75%) and user acquisition (25%).

Inbox When Ready Screencast

Up to this point, the extension simply made your Gmail inbox hidden by default and added a show/hide button to the Gmail UI.

After talking to a bunch of users, I came to realise that my initial vision for the extension — protect your focus, hide your inbox by default — was too narrow. I realised that a lot of people have horrible inbox workflows, and could benefit from an interface that actively tried to help them cultivate something better. So my vision for the extension became "protect your focus, cultivate a better email workflow", and I started experimenting with a handful of features to address this user need.

Feature development at this stage was guided by a mix of qualitative feedback and my general reading and intuition. I realised, though, that it was going to be hard to decide which new features were "keepers" without detailed quantitative usage data.

So I invested several day's work in setting up usage analytics and feature flag infrastructure that would let me A/B test new features. I was hoping to conduct epistemically robust experiments to gauge the effect of new features on key behaviors like the number of times people clicked "Show Inbox" each day, and the amount of time they left their inboxes visible.

This investment turned out to be somewhat premature — my userbase was too small to power many of the tests I wanted to run. So most of my decisions during this period were guided by qualitative feedback and less robust quantitative measures such as "what fraction of users enable and keep using this feature".

How have you attracted users and grown Inbox When Ready?

I got most of my first 100 users via manual outreach. I made a list of several hundred people who I thought would be interested in trying Inbox When Ready and contacted them individually, mostly by email. To make the list I:

  • thought about all my friends, colleagues and acquaintances who might be interested
  • searched the Chrome Web Store, Twitter, and Google for people who had said lukewarm or negative things about an extension which addresses a similar user problem in a different way
  • searched the same places for people who were clearly Gmail users interested in email productivity.

I wrote a short email with a clear subject line. I sent the emails via Mailgun's free SMTP service, which makes it easy to track open rates and spam complaints (I received zero spam complaints, which I took to mean I was emailing the right kind of people in a reasonable way). About 20% of recipients gave the extension a try. Crucially, a decent fraction of these people kept using the extension and began endorsing it on social media and the Chrome Web Store.

After passing the 100 weekly active users mark I kept going with manual outreach but shifted my focus to "supernodes". This led to endorsements from people like Tristan Harris, Ezra Klein, and Eric Barker, a trickle of press coverage, and a feature on Product Hunt.

I also added a few features to the extension to encourage people to tell their friends: a dialog that shows after you hide your inbox 20 times, and an automatic email that comes after you load the extension 50 times.

Here's a look at Inbox When Ready's usage data over time:

Month Active Users
Jun 0
Jul 26
Aug 22
Sep 225
Oct 404
Nov 810
Dec 844
Jan 788
Feb 1206
Mar 1402
Apr 1519
May 1644
Jun 1760
Jul 1744
Aug 1850
Sep 1959
Oct 2078

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

Inbox When Ready hit 1,000 weekly active users in winter 2016. By this point, I was confident that a decent fraction of these users were getting some real value from the extension — on the order of 30-60 minutes of focused work reclaimed every week. I also felt like the product could become 2-5x better with another 6 months of full time work, and potentially help tens of thousands of users realise wins of this magnitude. So it was time to think about my long-term commitment to the project, and with that, monetisation.

As a first step, I made a Patreon page and emailed it to a few hundred of my most engaged users. A handful of users kindly pledged their support, but it was clear within a fortnight that a donation-based model was not going to be sustainable.

I looked at how other popular Gmail extensions raise revenue, and decided to go for a simple freemium model. The free edition of the extension adds an "I'm using an Inbox When Ready" signature to outgoing email — if you don't like that, you can pay $36/year for the PRO edition. Everyone gets a 14-day free trial of the PRO edition when they sign up.

This project was never mostly about the money, and overall I am already delighted by the returns.


I don't love this model — the signature, as a growth hack, doesn't sit comfortably with my views on the ethics of attention (it strikes me as a moderately objectionable form of attention pollution, since it relies on interrupting the focus of email recipients).

On the plus side, the signature lets me provide all features to all users, rather than making a subset of features "paid only". It also serves as a fairly compelling "please upgrade" stick for professional users, which is the subset of users I feel okay about asking to pay. Overall the signature has been working quite well, but I hope to figure out something better soon. In the meantime, I invite people who can't pay to claim a free PRO license.

Monthly revenue has been fairly stable since launch. The monthly variation is mostly explained by variations in the number of people who visit the Inbox When Ready website or the Chrome Web Store listing, which itself spikes from time to time due to press coverage or influencer mentions.

Month Revenue
March 108
April 918
May 1514
June 1152
July 972
August 1908
September 1008

Note: March was a partial month.

I track all the time I spend working on Inbox When Ready, so I can tell you that as of October 1, 2017, I've spent 568.5 hours working on the project, and my all-time effective wage has been about $9/hour.

For my personal finances, the trend in my marginal hourly wage is what matters. It's heading in a good direction; in the past 3 months it's grown from ~$50 to ~$60/hour.

From a narrowly financial perspective, it'll take a while to recoup the initial time investment, such that my all time effective wage looks similar to what I could have earned by just doing freelance work. But this project was never mostly about the money, and overall I am already delighted by and grateful for the returns I've received on my time, in the form of learning, friends, and fun.

What are your goals for the future?

This time next year, Inbox When Ready should be at least 2x better and have at least 10,000 weekly active users. My dream outcome for this project would be to usefully influence the designers of Gmail and other major email clients (which between them have over a billion monthly active users!).

In comparison to that possibility, my personal goals seem fairly trivial. But they include: keep learning (about product development and user acquisition in particular) and have fun helping strangers (I get thank you emails every week, which is really satisfying). The extra income is nice too, and could be fairly life changing if things go well.

The biggest challenge is that I'm severely time constrained. I can work on this project about 3 days/month, and this won't change anytime soon, since I'm strongly committed to my day job at 80,000 Hours.

My default plan is just to push forward on product development and user growth in the time I have available. My progress will be slower than I'd like, but that's okay.

I'm actively looking for potential collaborators — I'd love to hire or partner with someone who can work on product development and/or marketing and growth. I've also had a few acquisition enquiries, and I would consider selling if I found someone that I trusted to take the project in a good direction.

What are the biggest challenges you've faced and obstacles you've overcome?

Time constraints are my biggest persistent challenge. I try to stay focused on the highest value activities and say "no" to everything else. In general I prefer automation to outsourcing.

I've put quite a lot of work into keeping the customer support burden manageable, mainly by addressing the root causes of common queries and optimising the handling of enquiries with templates and scripts. I usually spend fewer than 30 minutes a week on customer support, and I'm dragging my feet on outsourcing because it turns out I love doing it, and people seem to appreciate the fact that they're getting support directly from the maker.

In the last six months, user growth has been a bit slower than I would like. There's a lot I can do on the product development side to address this — onboarding could be 2x better, and I've a long list of ideas that could make the extension more useful for more people and thereby improve long term retention.

At the top of the funnel, I've yet to find a repeatable activity of the form "do X and Y new people will try the extension". If I could figure this out, I'd be able to invest more heavily in product development (e.g. hire someone) with greater confidence.

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

If I were doing this again, I'd start charging soon after passing the 100 weekly active users milestone.

It's just such useful feedback that people are willing to pay, and paid users, once invested, often take the time to provide especially valuable written feedback. I'm pretty sure the product would be better, and have many more users, if I'd started charging sooner.

Have you found anything particularly helpful or advantageous?

I went through Y Combinator with 80,000 Hours in 2015, and this experience helped a lot. A lot of YC's basic advice is just extremely valuable, and the feedback you get during the program is a kind of training which helps internalize it. For people just starting out, "launch before you're ready", "find people that love your product" and "you can always do less" strike me as especially valuable YC maxims.

In general, staying focused on the highest value activities is very hard and very important. My own process for this is to make daily, weekly, monthly and quarterly plans, and at each level of planning to search the possibility space and then do Fermi estimates on the costs and benefits of all the things I might work on that seem promising. These estimates often reveal big differences in expected value that are hard to see intuitively.

These books helped me a lot, and I would recommend them to all Indie Hackers:

  • Running Lean by Ash Maurya — for his emphasis on speed, learning and focus.
  • Value Proposition Design by Alex Osterwalder — for the advice on user research and ideation.
  • Traction by Gabriel Weinberg — if you want to start a business, it's worth thinking about distribution before you start making.
  • Getting Results the Agile Way by J.D. Meier — I've read embarrassingly many books on personal productivity. This is my favourite.

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

If you're still searching for a problem to work on, Spencer Greenberg has a great talk on deliberate innovation. Among other things he points out that you'll be better placed to generate new and valuable ideas if you cultivate a rare conjunction of skills and domain expertise.

In general I'd love to see more indie hackers think about how their work could help address some of the world's most pressing problems. Even if you're not well placed to work on these problems directly, you may be able to use your skills to make people who are working in these areas much more effective.

Our daily attention environment is surprisingly hostile. A lot of actors have strong incentives to misdirect us.


Where can we go to learn more?

You can find out more and try the extension at the Inbox When Ready website.

I'm on Twitter, Medium, and my personal homepage is here.

I'd be glad to answer questions in the comments. :)

Peter Hartree , Creator of Inbox When Ready

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  1. 3

    There are so many apps nowadays trying to steal our attention that it is great to see some helping us reclaim it.

    Great job and I hope it continues to spread. Good luck Peter!

    1. 2

      Thanks Gui :)

  2. 1

    This was a great read. Thanks for taking the time to put together such interesting and well-written responses.

  3. 1

    I'm keen to build something similar which integrates with GMail, though Chrome Extensions are somewhat alien to me. I know you have years of web dev experience behind you so this wouldn't have been a huge step, but do you have any advice/ resources for someone looking at building something similar?

      1. 2

        These are awesome - I had no idea about inboxsdk! That massively simplifies thing. How did you go about handling the authentication/license side of things, given that Chrome extensions are pretty much just pure JS and the code is completely visible to the users?

        1. 1

          I setup a web server. When the extension loads, it checks in with the server to verify the license.

          the code is completely visible to the users?
          Anyone with programming skills and sufficient motivation could download the extension code, modify it to disable the license check and enjoy the PRO edition for free. I don't lose sleep over this :)

        2. 1

          This comment was deleted 4 years ago.

  4. 1

    extremely solid on the details, kudos on the interview!

  5. 1

    This comment was deleted 4 years ago.