Surely someone out there has a commercial board and generates revenue from advertiser and merchant sponsors. What do you use and if you had it to do all over again, would you do the same thing?
That's a slippery slope.
My site is just a hobby and have resisted advertiser and vendor sponsors.
We are totally self-sufficient with google adsense and site supporter donations.
You will need to moderate any negative posts towards a vendor/sponsor.
I see it on many forums, posts deleted, people banned.
Entirely up to you of course.