My only semi-related experience was being a "lead generator" for commercial telecom (I think I missed out on whatever the "easy money" was in affiliate marketing during this time period) from around 2004-2009ish. I had sites that ranked for things like T1, ethernet, dedicated, mpls, var, and local KWs. A business owner would request a quote for a service and it would immediately go into a "closer" pool of experts. If they closed a sale, I would get a lifetime residual of a 15/85 or 20/80 split or so. I still get paid for sales I made in 2004, and prefer that over getting paid per lead. I think the same company (this was through a company with many vendors and an agent program, if that wasn't obvious) tried a pay per lead program that didn't work out.
Obviously that's different than straight up selling leads, but that's what I would look for. First figure out what kind of "leads" you are going to get and then find out who buys them or offers an affiliate program that would make more money for that niche.
If you can get traffic that results in quality leads, you can get paid. There are just different ways to do it.