Sort of going against the grain here, I've done two mobile apps that are doing well. I was able to grow them because I know Facebook virals really well, and we

Sort of going against the grain here, I've done two mobile apps that are doing well. I was able to grow them because I know Facebook virals really well, and we iterate like crazy, do lots of split testing, and they are in verticals that are sort of amenable to such things. No money spent on promotion of any kind either.