Here is an example of one:
You surf into an Ebony only site, and it says on the opening page that it contains 500,000 pictures inside.
You like black chicks with big asses so you signup, only to find that the ebony selection inside comprises only 10,000 pictures and the rest of the pictures advertised are from the sponsors other niche sites, of which you are not interested in.
False advertising or creative marketing?
As for chargebacks, check out
GloBill's refund policy.
I think they scare the surfer from attempting to commit fraud. Keeps the refunds at 0 and the chargebacks very low.