It's so obnoxious and makes me associate HATE with the products being advertised rather than a desire to buy them.
Every other form of advertising shares time and/or space with the actual content you're trying to view. These video-overlay adverts obliterate the content.
I've watched videos on some sites where the ad pops up at the bottom and obscures an important part of the image in the video. It's bad enough that you have to keep clicking the X to see the full image; when you actually have to rewind to see important content it's gone too far.
Advertising should either pause the video or not overlap with the video.
Maybe someone clever will find a way to block the overlays.
I'd use such a thing. I disagree with removing advertising in general -- I don't run AdBlock -- because it hurts the sites but I'll never hesitate to nuke advertising that interferes. After all those Flash adverts which played loud noises out of the blue, or appeared on top of the article I was trying to read, or used 100% CPU I blocked Flash by default (with a whitelist), and I'll block these stupid overlays if good extension / proxy / whatever is made to do so.