I have only just discovered this form of advertising, when I stumbled upon it on a video, I did some research and apparently it was being tested in 2009, perhaps it’s also been there or it is making a comeback. I have only encountered this form of advertising once.
Youtube gives you the options to choose what type of ad you want, and if you don’t choose they will play an Ad anyway, which really means you have no choice in the first place because you have to watch an ad.
I didn’t like it I prefer the ‘Skip this ad’ option rather than having to choose between a 2 min ad or a 30 second ad.
With Youtube struggling to monetize with advertising, it is no surprise they are experimenting with ads.