8 minutes is the cutoff for "mid-roll" ads (you can insert ad breaks into the middle of your content, not just the beginning and end).
But people also realized, especially in the past couple years, YouTube seemed to tweak the algorithm to favor watch time more strongly than in the past, so people started "fluffing up" videos to 20, 30+ minutes. As long as they could get a click with a decent thumbnail and title, and enough people to watch for at least a few minutes, the average watch time would go up, which was a very positive signal. Plus, they could insert like 3+ ad breaks (some big creators insert 6+!) and make more money.
However, in the past year it seems like YouTube's tweaked the algorithm again to not favor watch time as strongly over some other metrics, leading to shorter videos being able to get more views sometimes (and not just music videos). (But they're still "less monetizable".
I think this is why podcasting (and especially extremely long podcasts) have gotten so popular. A few thousand viewers watching for 2 hours gives a lot more ad revenue (especially if you fill in that space with read ads) than like 1 million views on a 3 minute clip.
But people also realized, especially in the past couple years, YouTube seemed to tweak the algorithm to favor watch time more strongly than in the past, so people started "fluffing up" videos to 20, 30+ minutes. As long as they could get a click with a decent thumbnail and title, and enough people to watch for at least a few minutes, the average watch time would go up, which was a very positive signal. Plus, they could insert like 3+ ad breaks (some big creators insert 6+!) and make more money.
However, in the past year it seems like YouTube's tweaked the algorithm again to not favor watch time as strongly over some other metrics, leading to shorter videos being able to get more views sometimes (and not just music videos). (But they're still "less monetizable".
I think this is why podcasting (and especially extremely long podcasts) have gotten so popular. A few thousand viewers watching for 2 hours gives a lot more ad revenue (especially if you fill in that space with read ads) than like 1 million views on a 3 minute clip.