Best Billboard Ever

I was walking back to work today, after a lovely lunch at the awesome McDonald's on 600 N Clark in Chicago. As you head west down Ontario, there is the best billboard ever up on the south side of the street on the side of the Ontourage building, across from Gino's East.

In case the picture is too small, it reads:

Hi Steven,
Do I have your attention now?
I know all about her, you dirty, sneaky, immoral, unfaithful, poorly-endowed slimeball.
Everything's caught on tape.
Your (soon-to-be-ex) Wife,
Emily
p.s. I paid for this billboard from OUR join bank account

Now, I don't know if this is real or not. If so, I'm hoping Oprah calls this woman and puts her on her show, because I think this is awesome. There is no logo or anything to identify it as being an ad - though ads have been sneaky before. I can't possibly imagine what this would be an ad for, though, so I think it's for real.