These are all ways of getting commissions/payments for your advertising services:
CPA - obreviation from "Cost Per Action", means that you get paid after the reffered trader opened a real trading account and made a deposit. In some cases, forex affiliate programs require a trader to make certain amount of trades to be qualified as "real customer". Only then you get the payment.
CPC - obreviation from "Cost Per Click", means that you get paid for each click on a link that leads to represented broker site.
CPL - obreviation from "Cost Per Lead", means that you get paid for every lead generated (lead is usually a completely filled out registration of a referred trader for either demo or live account).
CPS - obreviation from "Cost Per Sale", means the the amount paid per sale generated from your affiliate link.
There is also CPM, which you havent mentioned, but I will explain anyway!
CPM - obreviation from "Cost Per 1,000 impressions, means that you get paid an agreed payment for displaying advertiser's banner for 1,000 times. By the way, in case you didn't know M stands for Roman representation of number 1,000.
Hope this clears things up bit
