CPA marketing - You get paid for sending a lead.
Affiliate marketing - You get paid when someone makes a purchase.
How much money can you make with CPA?
This depends on the size of your network & the influence you have over these people. It is un-likely that CPA marketing can generate a six figure income for most people, but it can bring in some extra money with little effort once you are set up properly.
The greatest down-fall's that you can be recognize as a spammer. Ever had friends on Facebook that promote a club every weekend with super annoying Facebook posts? you might join their club.
CPA & Affiliate marketing are definitely not for everyone!