I right-click banners, and select open in a new tab.
I actually went to one of them, but usually just close them all down when I'm done checking this forum, my guild board and emails.

The content of the banner means very little.
If it interests you, check it out.
If it doesn't interest you, its a means to an ends.
And the end result is this excellent site, which is worthwhile.

I'd personally vote to leave the banners up indefinitely.
Not because I want the banners, but because this site is worthwhile.