Like couchsurfing but airbnb

We know couchsurfing, stayning some nights at some other peoples bed or sofa. All runned from the sight, couchsurfing.com, where you can find your host who describes the place with pictures and feedback from other couchsurfers. The same about you; you get some comments about you living in the place which your host can read before she or he desides to have you over. All this is for free. Now comes something else, airbnb, is like couchsurfing but you pay a little. Same idea but better? Take a look at airbnb.com.

With new cellphones and systems of feedback and paying this is now possible. Getting to know the culture, getting to know new people, making friendship is known from couchsurfing but now too, helping a little with rent and so on. Might this even be better than the free couchsurfing?