So right now I'm building a WP site which will be offering a free service, in exchange the user signing up for a specific affiliate offer under me. My dilemma is in trying to figure out what the best way to track who completes the lead, so that I can provide them with my service in exchange. The way I see it right now is that I need to create some sort of order/signup process where a unique and INFORMATIVE subid is appended to each users link, thus allowing me to match them up. I'm thinking the easiest would be if the subid was their "username" or "email", but I'm not sure how to achieve this. I'm pretty ignorant when it comes to PHP, but I've tried to create a form using several different WP plugins (CForms II, Contact Form 7, etc..) and then tried to call the variable using the $_GET function but I haven't been successful. Does anyone have any specific suggestions to how I can get this working and with what plugins/functions? Thanks!