For whatever reason, various groups at Microsoft love to run banners and posters that promote their products on campus. I'm not sure why they do it, I'd think that their money would be better spent advertising to (say) customers as opposed to advertising to co-workers, but hey, I don't control their budget.
Recently there's been a relatively cryptic series of banners circulating near my building that originally was a series of pictures of the back of people's heads, and recently changed to a series of faces (all with no text).
Yesterday I was on a shuttle with one of the PMs in my group and the conversation went something like this:
PM: Do you have any idea what those banners are advertising?
Me: Yeah, I figured it out a couple of weeks ago on my walk. They're Microsoft Advertising.
PM: I know it's Microsoft advertising, it's blindingly obvious that they're advertising something.
Me: No, it's Microsoft Advertising.
PM (somewhat exasperated): I know it's advertising. I'm just trying to figure out what they're advertising.
PM: If you don't know, then why did you tell me you knew what they were?