I found it rather annoying myself and it wouldnt totally disappear when clicking the X, still hiding BM information at the bottom.
I use firefox and use the App: Adblock Plus.
To eventually get rid of the banner, I had to go into Adblock and manually block all elements related to the banner. Got rid of it in the end.
I do agree with the message being put across, but unfortunately it was disruptive to elements of gameplay.