> What did the first iteration of this product look like? Was it more or less similar, or substantially different from the spirit of httptoolkit today?
Technically, the first iteration was https://github.com/httptoolkit/mockttp - an HTTP integration testing library for JS. Not a desktop app at all! I'd originally built that for testing uses, but as it matured I realised that with a UI and automated setup tools it'd be useful as a complete product (but Mockttp still powers all the internals today, and you can use it directly to build your own custom intercepting proxies too).
For the first real product, the very first public 'launch' was literally a landing page with some demos of the potential UI and a signup form, just to test interest and check it wasn't a terrible idea. The results looked promising, so that was followed a few months later by a very basic but usable free version (entirely read-only, and only supporting Chrome interception) with the freemium features on top appearing a few months after that. From this stage it was all very much the same spirit as today, just less feature complete.
> How did you go from (some semblance of a product) to first sale? / acquiring first customer?
Once I announced the paid version (a blog post to my tiny set of newsletter signups, plus a little response on HN/Reddit/Product Hunt etc) I got a handful of paying customers (but certainly less than 10) within 24 hours. Nice but not a meaningful income, and from that wild peak it dropped back down to maybe one new customer per week or so afterwards, so it was quite slow going at the start.
However, those paying customers (and the mere fact of offering a paid service generally) resulted in _much_ better feedback. Rather than "this is cool" all of a sudden I had real demands for specific features, from people with concrete use cases and money in their hands. The initial paid features were just made up off the top of my head, and honestly didn't create a particularly compelling paid feature set. It's very hard to really know what people will pay for! That feedback was incredibly unbelievably useful to fix that.
From there, building out the key features people asked for over the following 6 months boosted things very significantly, and started to get things moving for real, and then you get into a virtuous circle, where more users => more feedback => better product => more users => ...
> did you spend anything on marketing/distribution?
I tested advertising at a small scale for a few months, but it didn't really work great. I think largely because it's very very freemium - 99% of users pay nothing - so the acquisition cost for a paying user doesn't make sense, and also honestly I don't have much experience with ads and I'm not sure I'm any good at writing them.
Content marketing meanwhile has worked great, keeps passively returning dividends, and cost nothing. I've tried to fill the blog (https://httptoolkit.com/blog/) exclusively with detailed & high-value original content (detailed breakdowns of a recent HTTP security vulnerability, not "top 10 HTTP libraries for Python") which shares well on social networks for an immediate burst of traffic, and then (in most cases) provides both a long-term SEO boost and constant incoming traffic on related topics that converts into users. That starts slow, but again steadily builds up over years, if you keep working at it. Content marketing + SEO are pretty much the only marketing channels I work on right now.