Edit: Sorry, I just found the definitions section above 
I'm interested in some offers on my affiliate network, but they say "no incent traffic"?
What does that mean? Does it limit the kinds of landing pages I can use?
Well, to answer the question anyway since the post is here and people might search for it.
No incentive traffic is basicaly just you cant lure them with promises if they complete a action from the network's offerlist.
A good example is a game coin generator, where you asked the visitors to complete a survey before they could get their game coins.
Yep, incent traffic is just that "incentive" - you're offering an incentive for filling out an offer
The quality tends to be lower for advertisers as the consumer is filling out the offer not for their own purpose but to access whatever you're giving to them