I agree with ramster - I see a lot of text links that are really walking the line...whether or not the site is accepted will often depend on other factors too.
If you put a "Join here" even without the sponsor name, I would feel better about it. eg: "Real live CHAT WITH BUSTY GIRLS
IT WILL BE HUGE SUPRISE FOR YOU - JOIN HERE"
It's hard cuz being in the business it's pretty obvious to me; even for seasoned surfers I think they realize that when they click a link they will be asked to eventually cough up some cash. Try to put yourself in the mind of a newbie surfer who has never seen this before then you get an idea of what is blind.
just my $0.02
Ponygirl