I'm sure Marco Arment is doing just fine money-wise even after Apple basically integrated their own version of Instapaper into iOS, but he also co-founded and then left Tumblr in 2010. Yahoo just bought it for $1.1bn making David Karp a very rich guy.
@marcoarment
If anyone buys Tumblr, people are going to assume I’ll have a lot more money than I really will.