I think you guys are in a unique situation where you have the power to let a copy cat pass or not pass. That doesn't happen to everyone. Not everyone owns the platform.
Thanks zaidf. Sorry about the confusion. We actually mean that we (as the platform) are making a $340 CPM. The advertiser in this case is making closer to a $500 CPM.
I actually made an online course with some of my basic "tech knowledge". Now if a friend asks me, for example, about the process I went through to create a Facebook application, I send them to my course. I obviously won't charge my friends for the course.
I still get questions like this and have recently started to refer my friends to Quora.
Ultimately, as you mentioned, the overall lesson is to learn how to say 'no'. You can do this with respect and tact.