Kind of the AOL of the modern era, if you think of AOL culturally in the 90s, twitter is in the same spot today.
There is also a lack of purpose, lack of elevator pitch. By that I mean I don't know what twitter is for. Originally, right after I found out about it WRT SXSW, its the AOL-ified IRC on top of SMS text messages. Then it morphed into brand spam delivery for AOL users who can't figure out RSS from either the spammer or recipient side, be sure to follow our corporate PR dept because... well just because. Now its apparently going to be the AOL of photo sharing for those too confused by the complexities of facebook photo sharing and snapchat. But what is it, assuming my joke about them being the AOL of 2015 isn't just a joke (or ... is it?)