Is the content that's generated from post exchanges and packages really organic? I mean, people are only posting on your forums for a reciprocation, they're not there because they want to be, it's forced upon them if they want such posts matched/returned, etc.
I tend to be sorta active on most forums I do a exchanges with. Hoping they do the same. Which they do.
It's not really organic, but it can be. Post exchanges shouldn't be used to flood your community - you should use them to benefit you, and then after the exchange is done, keep on posting/