Been using Firefox for somewhat over a year now, pretty much ad free at first and I like ad block but new ads are being made with different url's all the time.
What I mean is advertisers are catching on to people switching to FF so they make ads to hit FF now more often.
However considering it still runs on windows I'm not surprised, got to hand it to the Moz people, way, way better than IE, even on Billy's turf.