One of the problems facing product manufacturers who want to get their product in front of your eyes is the tension between grabbing your attention by inserting ads in an entertainment experience vs. making the information 'so valuable' that someone actually seeks it out - e.g. 'must watch media' vs. 'must watch ads'.
Of course the 'watch' metaphor in today's attention economy isn't the right verb for the ADHD generation. You know the type; a teenager doing homework while simultaneously holding online chats, playing a MMORPG, talking to someone else on the phone, answering mom who's calling for dinner and playing poker (and winning).
That's why ads in SecondLife (product placements if you will) or other social networking venues work so well. They take advantage of an alreay established social network to interject their product in context; if there is real value in the product there will be real value in the network, with all the viral marketing implications intact.