I receive and usually read the Groupon emails even though I'm yet to actually buy anything, but I think that the emails are significant because they make it easy to share Groupon deals with friends. As I said I haven't actually bought anything but fairly often people ask me if I know about "that coupon thing" many of these conversations end with me forwarding a deal email or two, or just adding their email address to Groupon's mailing list (with their permission of course).