Because they weren't better than Twitter at their core competency, nor did they provide a cleaner user experience (Google and Facebook beat Altavista/Yahoo/Mysp

Because they weren't better than Twitter at their core competency, nor did they provide a cleaner user experience (Google and Facebook beat Altavista/Yahoo/Myspace/Orkut/Friendster by doing exactly that). The mp3 sharing feature? It hasn't compelled me to try pownce, there are already music-sharing social networks (pandora and LastFM) and I can paste a TinyURL'd link to youtube containing music or video into Twitter just fine. As such they had no defensible technological advantage ("have a feature before someone else" isn't). They didn't have a strong technical person, all they had were decent web developers (Facebook's Dustin Moskowitz seems to be fairly talented and I know they had a very strong operations team; Google had backing of academia behind). They could have still been a niche site and profitable, but they instead chose to burn their money on PR (this is clearly evident) hoping to "get big fast".