What is Epsilon and why does it have your email?[ Mon, 4 Apr 2011 23:25:24 GMT ]Before this weekend, you'd probably never heard of Epsilon Data Management. But the Texas-based marketing firm had almost certainly heard of you. In fact, the company behind the high-profile leak of data belonging to Best Buy, Target, The College Board, Walgreens and other big-name firms probably has an intimate relationship with you.