ember - 5:32 pm on Mar 11, 2013 (gmt 0)
For those that don't know, this has been going on for a few years now.
Yes. When I now look at my site, I see ads for other websites I've just visited and ads that match the general content of other sites I've visited recently. My visitors are not seeing those same ads. I also see ads that match my content, and these may be contextual ads which my visitors also see, or they may be ads for other sites that I visit that are in my same niche.
It's confusing, but the bottom line is you cannot look at your site and know for sure what ads your visitors are seeing. Google is putting ads on your site that it thinks will make the most money, whether they match the content of the site or the behavior of your users.