TrueView ads are the main video ad chosen by advertisers because you only pay for the cost of the ad when consumers watch or interact with the ad, and the videos can be easily designed to share a wide range of content. advertisers only pay when a consumer watches their specific ad until the end or for at least 30 seconds. The other way an advertiser would pay for a TrueView ad is if the viewer interacts with the ad, such as clicking on a call-to-action button or clicking the link to be brought to the website. YouTube as a platform requires that skippable TrueView ads must be between 12 seconds and 6 minutes long and that the non-skippable ads be no longer than 15-20 seconds.
In-Stream Ads
In-stream ads can play at almost any point of a YouTube partner's videos, whether it is the beginning, middle, or end. Consumers are given the option to skip the ad after 5 seconds of the ad running. If the video ad is at least 30 seconds, the advertiser is charged once the ad reaches that 30-seconds of watch time. With shorter ads that are less than that 30 second mark, you're charged only if the entire video runs. In-stream ads allow for marketers to have more customization in their video ads with different call-to-actions or ad text.
In-Search Ads
In-Search Ads are displayed in search results when specific keywords are searched and aren't played until someone selects the video. You're charged once the user clicks to play the video.
In-Display Ads
In-Display Ads or also called Discovery Ads, appear next to other related videos on the YouTube Watch page and are labeled as an ad. The ad is charged once the viewer clicks to play the video, the destination video page also features an area on the right-hand column where a companion banner display ad will appear. Another important note is that a single advertisement can appear in many different formats, allowing you to test which one of the formats works best for your product, or service.