This is remarkable, even to me. The main point: if you're doing a startup, things take a long time. Longer than you'd expect. And overnight success is anything but.
That's actually kind of a relief, especially considering all the news you hear about 10000 users in 72 hours, it seems like if you don't explode onto the scene you're a failure.
"Timing, perseverance, and ten years of trying will eventually make you look like an overnight success." -Biz Stone (co-founder of Twitter)
Personally 160 users sounds like a lot to me. None of the unfunded services I've bootstrapped had reached that.
Mind you, these aren't paying clients or anything, just a 160 twitter accounts. At the time you had to have it created FROM a mobile phone, so the onboarding process was clunky. We were showing it to our friends, tell them how cool it was. A team of 10, with 3 months to pressure their friends and family in to using the service, got 160 users.