If you guess that one, I’ll buy you a beer.
When it comes to web applications, Richard White‘s answer is one.
“You only get one shot to impress people; don’t blow it because they won’t coming back next week to see if you’ve improved.” (link)
This is one of the lessons he draws from the demise of his employer, Kiko. Because of a less than perfect first version, nobody seemed to notice the much improved 2.0 release. With a disappointing adoption rate, the founders eventually lost their motivation and called it quits.
While it seems like a strong argument, I don’t think it is actually the right conclusion.
Whatever your target market may be, your pool of potential customers who have never heard of your service is much larger, by several degrees of magnitude, than the people who actually tried it. You may leave the early adopters unimpressed but if you can learn from them and focus on your next users, then you get another chance to make a good first impression.
So how many times can you make a first impression? About 1,043,000,000 times, which is roughly the number of people using the internet these days.