The idea behind <a href="http://www.groupon.de/" title="Groupon" target="_blank" rel="noopener">groupon</a> is to make it easy (and cheaper) for new customers to try out a service or product. The whole site really looks like racket but I used it some time ago. I have the common practice that I create an e-mail address for every single service I register to. So I used an e-mail address of the style "mymail-groupon@mydomain.tld" for it. Today I got an e-mail with the subject "Abmahnung Ihrer aussehender Rechnung über 262,00 Euro" (impolite german for "Reminder for a payment about 262 euros") from an debt collecting agency. <a href="https://blag.nullteilerfrei.de/2013/04/05/groupon-sold-my-e-mail-address/#more-1723" class="more-link">Do you want to know more?</a>