"Either way, it is not illegal to sell a forum, which was my point."
Correct! Internet forums are bought+sold all the time.
This publicly traded company is in the business of buying forums: CrowdGather - Find it on Forums
We understand that forums are all about community and that community takes time and care. We are forum members, owners and community managers and this gives us the unique perspective to really understand the needs of forums. We know that if you are interested in selling your forum that you want it in good hands. CrowdGather is committed to your forum thriving and becoming more than what it is today through technology enhancements, search engine optimization and most importantly through engaging content."