Publicity stunts usually have a greasy exploitation feel to them. Even when they are entertaining, there is still the feeling they are trying to trick you into liking something that you shouldn't (Anybody watch the Bud Light commercials during the Super Bowl? - You know what I mean, right?).
Last year's skydive from space by Felix Baumgarnter was sponsored by Red Bull and was clearly a publicity stunt; a very, very expensive one at that. However the whole thing was fascinating to me and dang impressive. They have just released more Go Pro footage of the jump and it's worth watching. As he falls through the upper atmosphere, it is surreal to see how little movement there is in his clothing. He is moving a few hundred miles per hour and his clothing is perfectly still. He passes 800 mph (yes, 8-flipping-hundred mph) but it's when he is closer to 200 mph in denser atmosphere that he talks about "hauling ass". Really fascinating.