Out of curiosity, why don't you guys use ads on your board to fulfill the costs?
The only kind of ads that would make sense would be affiliate marketing through
"Friends of J-List" with its up to 12% comissions but we did some experiments, both with this and some Amazon Affiliate marketing and returns were minimal. First problem had to do with our young demographic and the other the high ratio of ad-block among our users. I certainly did some tests and it just wasn't a viable.
Our community's demographics puts 70% of our members in the 13-17 age range with approximately 65% female. Just with everyone being so young any eyeballs we have to possibly sell just aren't worth that much. We used to run on shared hosting but we just grew to big, at peak times there may be 100+ concurrent users, daily. Just used too much resources and we had to move to a VPS.
Likewise, we tried PHPBB and other free scripts before but there are some very specific features and plugins on XenForo that really appeal to my community. Seems like most of the community agrees. Not only fully funded our transition but got us 1/3rd through all our stretch goals with 20+ days to go!
And yes, we were rejected from IndieGoGo for having too small of a goal under their "fixed funding" option. They want all projects to be $500 at the very least, our start goal as you can see was $200 and $500 would have been much more than we needed and one harder to justify to the community.