My first startup started in mid-2000s. For identity reasons, I'm not going to list the name here (I prefer to stay anonymous), but it wasn't a typical silicon valley style startup. What I mean by that specifically was while we were based in San Francisco, majority of the bay area never even knew we existed.

Back then, Techcrunch wasn't very well known and I am not sure HN even existed. Majority of people were not blogging yet and we never thought about getting press. Perhaps because of the way things are now, and there is a lot of information overload, there is a lot of subconscious influence on how people perceive things and thus have a specific mindset when it comes to building a startup.

For better or for worse, we were not originally from this area and we didn't get exposed to any of the valley related stuff (total ignorance you could say) and because of that, we took a very different route even though we were building a tech startup.

We didn't really have a formal launch day per say (if people signed up during the beta stages, we never denied anyone from using the product or having to wait for an invite). We didn't even originally intend the idea to be a startup. It was an idea built out of necessity and something we showed off to our friends who got interested in using the product. It wasn't until some time later that the idea of making a company out of it (note the word company vs the word startup) came across our mind. When it became clear we wanted to build a company around the product, we got our small group of friends to help bring in more people who had a common interest in the product as well as reaching out to total strangers online wherever we could finding anyone who would be interested.

We spent countless hours and weeks just messaging random people online from anywhere and we probably got somewhere between 200-300 people using the product (I don't remember exact count, its been awhile). And while the rest of the world didn't even know we existed, we pretty much went through iterations to improve the product base on feedback through this group. This part was also accidental. This was before we ever moved to the bay or even heard of the term lean startup. None of that existed in our world at the time. Turns out this was the best way to do things.

This accident formed our "beta" group although it was never really intended to be such and when it was much better (the product), we started to reach out to people in the industry who had influence to check out our product. This got the ball rolling for what I guess could be considered a public launch but there was definitely no set definitive idea around what a launch day was. We began attending industry events and doing everything we could to spread the word while working on the product around the clock and slowly but surely the user base grew.

Two things to note from this. The first is I don't know how this compares to how others did things back then. The second is this may or may not be the fastest way to grow but our product was not a consumer facing product to begin with and this was before social and sharing became a de facto and things drastically changed on how fast you can acquire users today vs then. I am only answering this base on my first startup since this is what you were asking in reference to. Things are slightly different albeit still the same in a lot of ways. Hopefully it helps in some way.