Here is the link to that thread.
http://greenguysboard.com/board/showthread.php?t=62827
One thing I noticed was Greenies has a lot of popularity with MILF or Matures target audience. It really depends on what to promote I like to think of what I could see someone paying for. If it's a niche and I think that I don't know who would want to buy something like that than you pretty much are admitting you have no idea how you would connect to someone that did.
I personally have had success with BBW porn, but that's just me.