giamann, you came in honestly. You didn't get bashed. You got honest answers.
A TGP links to galleries. That's pretty much it.
As far as what Joe Smut Surfer wants, TGP's care less about sales then a true link list. TGP's are about traffic. Link Lists are about selling porn.
Submitting to a TGP is about getting traffic.
Accepting submissions from a submitter is about listing galleries to keep the surfer coming back (keeping traffic) and getting traffic from other TGP's listing that gallery.
A true Link List, like
Link O Rama, funnels traffic into niches. The surfer is given options, choices, to figure out what they're looking for. This makes sales much easier. Submitters are encouraged to be more sales savvy, and this makes sales much easier. Also, there are search engine bonuses to doing things that way.
EDIT: I did the tags wrong for linking to LOR. Had to fix it.