Does your topcashback email account have to match the one on your Amazon account for example? I've signed up using a new email address to get the new user £15 offer but my Amazon account and Lego and all other log ins are under my old email address. Does it matter? I'm confused how it knows you've made a purchase. It's logged me bouncing from topcashback to Lego but not to amazon. I'm totally new up it and am easily confused these days.