incrediBILL - 7:32 pm on Oct 10, 2012 (gmt 0)

Everyone can make copies but the original has such viral traffic and a loyal community that while they may steal the functions and features I doubt they'll make a dent in the overall usage at this point.

Facebook is the only one IMO that could actually be a threat and the interface of Facebook itself doesn't mesh with the Pinterest type environment, and the crappy Facebook search, which would be severely limiting factors.