This is the first that I've heard of this technique and I find it especially intriguing/annoying. Intriguing in that it's a new (to me) technique. Annoying in that it's yet another way to get unwanted ads in front of you.
And ABC wonders why people have a tendancy to skip commercials when they able to.
I also worry that this will become yet another vector for infection and exploit. Oh, and shame on you, Vonage, for encouraging the mess by funding it (in part).