There is a fantastic post on ‘On Startups’ (a blog I highly recommend) talking about why ‘me-too’ companies aren’t always a bad idea.

“Yes, there are competitors, but nobody has built a product yet that users really like…”

And there, quite simply is the crux of the motivation.  It is easy to discount companies as being “me too”, but the reality is we have seen a fair number of successes in the past in categories that we have felt were already crowded.  The reason is that nobody had really solved the problem quite right.  This is what motivated Matt, and this is why you shouldn’t let me (or others) talk you out of a startup idea simply because it might be labeled a “me too” idea.

This makes a ton of sense. Until the use case is really nailed, there is opportunity for new entrants. I think a critical element to consider, however is that your take on the idea shouldn’t require users to change existing modes of behavior. If they can do what they’re doing on the existing sites but get better results and more utility from you, then you’re on to something.