A way to block all sales and marketing for items that you just bought.

The annoying thing about buying stuff online is that you are now tracked and sent new "sales" stuff about other products similar to the one you just bought. For instance, I just bought a new motherboard. So New Egg decides to send me a bunch of sales stuff for other motherboards. This now puts me into anxiety mode because I know that I can't return the one I bought and now I'm being shown something similar that is cheaper/better/whatever. This sucks! All online retailers do this and I wish there was a way to block it for at least a few months at least so I don't have to worry that I made a bad choice.