I'm pretty sure most sites (eg. Amazon) does the same thing. Probably for the reason you mentioned: so they can have your contact information to send you spam later.
My girlfriend uses this as a pretty effective tactic to get discounts - you just have to wait a couple of days and they'll send you an email with a lower price to keep down abandonment rates
Haven't received any "items in your cart" emails from Amazon peronally, but I will end up seeing Ads for the products later on.