It seems a new service is so eager to get people to join their community that they are scanning new users address book and spamming everyone in it with a invite.
At last count this morning I have received about a 100 invites from the service and quite frankly there is no way in the world I would use it now meanwhile mailing list and personal email accounts are being bombarded.
It appears that these actions are being forced on people so stay away from Quechup.com