Following our TC launch, we were featured in other channels, which gave us more signups. 300 might not seem like a lot, but these figures are very conservative and we only counted users that really tried the app.
...which are the only ones that matter, no? So if only 300 "really" tried the app and 2,201,302 signed up, you obviously only care about the 300 if that's the number you're mentioning.
Why try to sound mightier saying "these figures are very conservative" and "we only counted users that really tried the app"?
Probably because they expect to get compared against other startups who are trumpeting "millions downloaded our app!" like it means something. Saying "these figures are very conservative" and specifying exactly what they're counting is a preemptive answer to people asking "how come you only got 300 when Startup X got 3,000,000 after the same amount of time?"
It means that we chose to report what we thought were the most relevant figures, because otherwise, comparing different channels would have been useless.
Now, they will necessarily appear smaller than what you can see in other blog posts. YC partners will tell you that most startups shouldn't expect an immediate rush of users and that success is built over time.
Following our TC launch, we were featured in other channels, which gave us more signups. 300 might not seem like a lot, but these figures are very conservative and we only counted users that really tried the app.