A couple of people I know got signed up for Quechup. My address was apparently "harvested" from the address book of these folks and I've been invited--multiple times, even--to join this service.
I've looked through this service and I see absolutely no reason to join this place. It looks like a lame me-too service with no obvious value. The fact they want an address book is very irritating. Given the relative intelligence on the Internet with regard to these matters, I suspect I will see a lot of spam related to Quechup. Even people who do know better occasionally get sucked in.
Bottom line: avoid these twits like the plague.