Clearly a lot do, but the concept, once shared, seems to live on. I find it particularly amusing that EBay, which pretty much defined the market for selling your junk online, has now moved so far that there are new startups like "LetGo" and the other one with the name I can never remember trying to be in this space. The concept continues, and the technology to implement it evolves.
As for the question, greed always hijacks progress, that is the lesson of the Prisoner's Dilemma.