As hinted at by other posters in the thread... the ads you get on BB are 100% based on your browsing history, and not specific to BB's site. I definitely never get those ads on my work computer, but rather a bunch of stuff about Adobe Creative Suite products and similar, since that's the sort of thing I browse at work. There are several other sites I visit that also use Google AdSense or similar, and I get the same ads on those sites as I get on BB, regardless of which computer I'm on (that is, on computer A, I get one set of sites on BB & the other AdSense sites I visit; on computer B, I get a second set, but the sets are the same on the same computer).
So, basically, it's not BB's advertising, it's your (computer's) browsing history...