> There isn't that many of them displayed for me (maybe one ad per 3-4 10-15min videos). One can skip it after 5s and around half the time those ads are fairly

> There isn't that many of them displayed for me (maybe one ad per 3-4 10-15min videos). One can skip it after 5s and around half the time those ads are fairly well matched. How many ads you see highly varies by person. Recalling Tom Scot's explanation that I fail to find, imagine when you play a video an auction is going where advertisers bid to buy your time from Google and winner shows you an ad, but Google also sets a minimum bid, so you don't see ads if nobody bids that minimum.