Maybe they mean they don't add ads before/during/between the videos, but leave in sponsored ads the creators put in the videos themselves.

Is there a better word for that? Is there a broadcasting term for the type of ads you'd see more in the '50s, ie. "This program brought to you by Lucky Strike! Hmmm, it's toasted!", where the ad is embedded into the show and not a separate block of 15, 30 second segments?