[thehappypm]

This is actually untrue. Have you ever seen a survey in a YouTube ad, asking a question like "have you ever heard of Brand Z?" That's one of several mechanisms for measuring brand awareness lift, seeing the lift in recall over a control group.

Likewise, many advertisers aren't doing brand campaigns, they're doing direct response, that is, trying to get people to directly click to their site and convert.

Finally, advertisers on video sites tend to pay per "completed view" for some definition of completed view, usually at least a significant chunk of the video and not just the first few seconds before the skip button appears.