MySpace,* for reasons that should have been obvious to everyone who used it, stopped being 'good enough' so people switched to another site. It is likely that people will abandon the evil that is Facebook at some point, but I am not investing a pile of money in creating an alternative. Google's ability to waste billions in trying to do so is down to producing good search results quickly at the moment that the previous leader jumped the shark and tried to 'go portal', otherwise the people would say 'just AltaVista it'.
In this context, being a bit prettier than AW is not enough and you'll need very deep pockets to last until you can have a hope of getting what they have: numbers. Even if AW do commit suicide, you still need to hope that it's your directory, rather than one of the hundred or so others, that accidentally gets lucky.
* .. and Friends Reunited and...