When you put your time and effort into something that you don’t own you are at the mercy of the third-party service.  Social networking sites like ActiveRain and Facebook are successful because of the users and members whom contribute to these sites.  The exposure and rewards that these sites offer to an internet marketer are large.  The more a person contributes, the greater the exposure and reward and so too the dependence.  If these sites change one component or policy, you could be out of business (or forced to change your business model, which may prove expensive).

You can and should use social networking sites for what they provide, but never invest too much time and attention into one platform or another.  You never know what these services may alter.