If your business model is dependent on being just awkward enough to use that you generate extra page impressions but not awkward enough that you drive away traffic, to borrow an aviation term you're flying awfully close to coffin corner. Particularly when you're dependent on network effects; if enough people start discovering something that's less awkward for them (such as OKC), the network effect will start working against you and you're suddenly so 2004 with a database of inactive users and a reputation for being awkward to use. Plus, if you're dependenet on awkward usability inherently generating more pageviews, surely by definition those pageviews are also more rapid so the time each ad is being displayed to each user is lower, so the savvy ad buyer would also be paying less.

Now, I could make the case that PoF has ridden the wave for long enough to build Markus enough money that if it all fails tomorrow he's still made for life and only really lost pride, but....