I didn't use the same email for D2D as i did with origin, So I'm not sure how they got my email. I shall see tomorrow evening if i get a free copyAll BF3 activates through Origin, I believe. So even though you might have bought it somewhere else, they just give you a code on Origin. I got Deus Ex HR on Steam from greenmangaming.com the same way.
Yes you can activate the key on origin, and one of the main ideas behind preloading is to keep stress off the DL servers when the game is released, i didn't have any issues downloading the beta @ 7MB/sI pre-ordered from EB and I just realized I don't have a functional DVD drive, I'm broke and my paycheck won't come for another two days after release. Can I just enter the code on origin or steam and get it digitally?