- display a static ad, have the "x" to close appear soon (3-10 seconds)
- display an animated ad, have the "x" to close appear soon (3-10 seconds)
- display a static ad, have the "x" to close appear after 20-30 seconds
- display an animated ad, have the "x" to close appear after 20-30 seconds
- display several ads in succession, each short, but it automatically proceeds to the next; the net time after which the "x" to close appears after 20-30 seconds
- display several ads in succession, each lasts for 3-10 seconds but you have to click on an "x" to close each one before the next one appears
I live in the USA. The well-established consumer product brands (Clorox, McDonalds, etc.) almost all had short ads that were done in 3-5 seconds. The longest ads were for obscure games or websites, or for Temu, and they appeared over and over again, making me hate them with a flaming passion. The several-ads-in-succession were usually British newspaper websites (WHY???? I don't live there) or celebrity-interest websites (I have no interest in these).
It seems like the monkey's-paw curse for this kind of legislation is to show several ads in a row, each allowing you to skip them after 5 seconds.