https://marco.org/2007/11/06/an-enterprising-developer-reads-these-articles-and
An enterprising developer reads these articles and thinks “I want to write an app that gets half a million users in 10 weeks. I’m going to do what they did!” So she spends a week in her basement and cranks out a Facebook application. When she uploads it she finds a few thousand users and not enough monthly ad revenue to buy a Frappuccino. Why is that? Because the vast majority of the traffic (87%) goes to 84 of the 5,000 apps currently on the platform. That’s less than 2%. Not one of the articles I’ve read has mentioned this ratio, or the enormous luck factor involved in creating a “successful” Facebook application.