The question you need to ask is.... how high of quality is the traffic you want. Your average TGP is chock full of hitbots, foreign traffic, etc. If you want tons of hitbots and non-english speaking surfers, go to your average TGP.
Go to somewhere like spotbrokers who doesn't count proxy traffic as hits against how much you bought and doesn't send any foreign traffic to your site at all. (you can see all the countries they redirect themselves for pay to the TGP or allow the TGP to send them elsewhere in the "junk traffic" area).
Now the opposites. Something like spotbrokers has catagories and subcategories, so maybe you have 4 lesbians with dildos and strapons, you could be listed under lesbians, and 4 lesbians. So people could use "lesbian gallery" which isn't prequalifying. If you went to a TGP, you could have a description such as "Mindy and three of her catholic schoolg*rl friends fucking each other with strapons" That will get you much more targetting traffic in terms of buying.
Just my
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