I don't think that's working very well (so far anyway). Most F8 app sites have experienced a significant drop in visitors, not a rise (look into iLike). I think that Andrew is on to something and that you should cultivate the social net on your own site and not give up so easily. Slow organic growth of your own property is more desirable than quick widget rise numbers on someone else's platform. Problem with F8 is that you don't own the relationship with the customer and you won't be able to monetize that relationship as easily. I'd give organic growth a try first and if that fails, go with F8... you have nothing to lose then.
