If we must have ads playing incessantly, which don't get me wrong, I understand the business need for them, how about we limit them to 10 seconds or less? As much as it still stinks to miss 10 seconds of a stream, it would at least suck less than missing like 30 seconds or so. It would be a nice middle ground between Twitch getting the ad revenue it needs and us, the viewers not getting interrupted.
Secondary idea to tag on to this: Warnings when ads are about to show up. Like youtube does, or did... or does? Give us like a 5 second warning before the ad starts playing so we at least have second's warning before it cuts to it. Sitting there just casually watching the streamer only for it to cut away with no warning is not fun. Give us warning, limit ad length, and I think we'd be alright.
I hate constantly watching ads of 30 seconds :/