That's more so they can bring you back even if you weren't actively looking for something ("wow, widget x is 50% off - I'll probably need it in the next few mon

That's more so they can bring you back even if you weren't actively looking for something ("wow, widget x is 50% off - I'll probably need it in the next few months, I should buy it now."). Also to keep their brand in the front of your mind the next time you do actively look for something.