One of the companies we featured in our ideas database is BuiltWith.
BuiltWith is making over a million in revenue per month. Here's a screenshot from our ideas database so you get an idea:

Let me explain.
A week ago, I wrote a post on social media scheduling tools.
The key building blocks of a social media scheduling tool are the social media platform it supports. X, Threads, Instagram, Facebook, you name it.
The maximum number of those "key building blocks" that a social media scheduling tool can support is probably no more than 10.
Because there are no more than 10 big social media platforms.
So if you were to create distinct products from a product like Buffer, for example, you'd probably create:
Let's apply the same logic to BuiltWith.
Unlike social media tools, a tool like BuiltWith has thousands of different key building blocks.
BuiltWith is a SaaS that allows you to analyze the technologies that "powers" a website.
The keyword here is "technologies". Each "technology" is a key building block, in the same way as each "social media platform" is a key building block for our previous examples.
According to BuiltWith, they track over 2500 eCommerce technologies across over 26 million eCommerce websites. And that's just for e-commerce.
For a social media scheduling tool, you could create a maximum of maybe 10 individual products. But if you take a product like BuiltWith, you could create over 2500 potential products. Let me explain.
Let's take Shopify as an example.
Why would someone care to look for websites that are powered by Shopify?
Now, let's take websites that run on Google Analytics.
Why would someone be interested in targeting/contacting people with websites that run Google Analytics?
My point is that the audience for each technology is vastly different from the audience for other technologies.
Each technology represents a distinct market segment with its own unique needs and opportunities.
People who are looking for Shopify store owners are (often) quite different from the people who are looking for Google Analytics site owners.
So here's the micro-product idea for you:
BuiltWith is quite expensive. These are their monthly plans:

You could take one (or two, or three technologies) and try to sell them an (updated) list of sites that use that technology to a specific target audience. Here are a few ideas:
Sites using Wordpress - sell this list to Wordpress plugin developers, theme creators, web agencies
Sites using Stripe - sell this to payment solution providers, fintech startups.
Sites using Zendesk - sell this to customer service SaaS providers, customer experience consultants, agencies that provide customer support staff, etc.
AI to the rescue: To get an idea of whom you could sell to, you could use a prompt and input it into ChatGPT/Claude: "I'm trying to sell a list of websites that run on [technology]. What is the potential target audience interested in such a list?"
So the key idea here is to "unbundle" BuiltWith; make each technology list a separate product.
You could also create a small SaaS where people pay a small amount each month (or a year) and provide them with an updated list (the list could be updated monthly/weekly/daily).
For example, Wordpress plugin developers can go to that website and get a constantly-refreshed list of new websites that just started running on Wordpress
BuiltWith charges close to $300/mo for getting access to 2 technologies.
A (far) more developer-friendly site is PublicWWW. They're a "source code search engine" where you can input a "signature" (each technology uses a different HTML/headers/CSS so you can recognize when a site is using it) and get a list of websites that use that signature. Here are a few examples.
The important thing is, unlike BuiltWith, they don't charge you by the number of technologies you export.
Another (albeit more expensive) alternative to PublicWWW is NerdyData. They also don't charge by the # of technologies you export.
Both of these companies go one level lower to what BuiltWith is doing:
BuiltWith already figured out the signatures and sells you a ready-made list of sites that use those signatures (i.e. technologies)
These "source code" search engines allow you to figure out the signatures on your own (which is not hard at all) and come up with your own lists.
If you want to go one level lower, you also have open source libraries like WhatWeb.
WhatWeb is essentially a self-hosted version of BuiltWith. They support over 1500 "plugins" (i.e. signatures) that identify the technologies different sites are using.
There's always a new technology on the block. BuiltWith has a trends page where you could identify some of these technologies.
The advantage of targeting a new technology: New technology means a new supply of websites using that technology. That means new demand for people who are looking to target sites using that technology (either competitors of that technology, products/services in an adjacent niche, etc.)
Hope you found this post to be useful!
checked. only 1000 top websites are shown under free plan in builtwith. Rest requires payment of $100 and they accept payment only in bitcoin. what a bummer.
paying $100 per month and only in bitcoin seems to be too much especially for indiehackers.
will look into other methods suggested here
Let's say i want to sell website list which uses hubspot to its competitor.
So dont you thing that competitor are also so advance they can extract or scrape this list by their own.. why they look for such service which they can do by themselves. as they are much more technological advance then individual indiehackers. Please guide.
This has helped me to now know where to go if I am interested in finding out a website technology! Thanks for the insights
Whoa, bookmarking this!
I love the idea! I think I've come across the same concept in a book, and it was called cherry-picking.
Great!
Nice post! Thanks for that.
I'd also throw in https://hunter.io/techlookup as a resource. Cheaper than NerdyData, but not as deep. So it may be a good middle ground, at a more reasonable price, for some folks.
+1 for Hunter. It has been around for a while and reliable when it comes to finding emails.