Can you elaborate on why this makes a difference? On the theory that people buy "sponsored" products because they wish to feel or display an affinity with the sponsor, James Bond, the fictional chracter, is a much more effective sponsor than is Daniel Craig, the actor.
I wish that I could be James Bond
with dry martinis, cars, and blondes,
a PPK, and sharp things to say
when I'm about to get it on
Maybe it comes down to feeling that the cost of #ad in the corner of the movie is much higher than the value of doing so.
How about when ESPN televises a NASCAR race. Ever car is covered in ads, do they have to have #ad on screen for the entire broadcast?
Although, if a disclosure rule that would lead to broadcasters removing their bug watermark in the corner came along, I would be all for that.
If James Bond went on a 5 minute spiel about how Smirnoff is the only good Vodka, instead of subliminal product placement, would that be considered an ad? How much of the movie has to be about Smirnoff before it's legally just a 90 minute Smirnoff commercial.
Medicine commercials on TV already have to announce that someone is a paid actor, it's not completely unheard of.
Daniel Craig is being paid to portray James Bond, but that doesn't need to be pointed out, right?
I suspect if movies had to put #ad on screen whenever a product is placed, it would be like the California cancer warnings. They would soon become meaningless and invisible.