For every niche, there would be only 1 winer makes money, 1 survivor hanging above break even line, 1 slightly below water wishfully thinking... everybody's else dead already. You have to run for the speed first.
Each story can't last long either, like the Groupon / Living Social, WebEx / GoToMeeting, My Space / FB / Monster...
Good thing about segmented business, like landlord here as a good example, it's easier for people to start and last longer. 小而碎也有好處,大鱷也不容易整合。要是沒有那實力,就不能處於四戰之地。