The Real Reason Hillary Rented Her Email List: To Get It Back

... Federal election law prohibits campaigns and super PACs from coordinating on expenditures - television ads, direct mail, and the like. But there is nothing stopping them from sharing mailing lists or volunteer rolls, as long as they are compensated ...

http://swampland.time.com/2014/01/07/the-real-reason-hillary-rented-her-email-list-to-get-it-back/