TGPs are better at generating a zooming a lot of instant traffic your way, rather than counting on them as the only way of making money (although it is possible).
If you got listed on The Hun daily for example, and burning up 60-75Gb a day you'd usually get about half a dozen signups each time.
Last time I got a
Bang Bros gallery on the hun I made $245 out of it very easily, so if you managed that on a regular basis...