I think that if Steem is as valuable a service as everyone thinks it is, it will naturally have a spillover effect into the rest of the interwebs. This is natural selection in action. The bigger steem gets, the more it will be talked about. But if the product is horrible, then the talking will be minimal. To manipulate other sites into joining, will only ensure steem's ultimate demise because people will see it as the origin of large amounts of SPAMing -- an image that frankly, our community doesn't want.