UPDATE: You thought I was kidding?
I know these tests have become popular for discovering ethnicity. Heck- I wanted to do it myself. I even ordered the kit. BUT you need to read the fine print and understand that in order to get your results, you are signing away your rights to your DNA sample forever. The tests are not destroyed, but rather maintained in a database for use in any way Ancestry.com deems useful/appropriate for however long they want. Think about that before you donate your sample.
Efforts to cancel my test and get a refund were less than successful. Give this scheme a pass, as I wish I had.