YouTube ads target you based on an algorithm similar to Google and Facebook

How does the YouTube algorithm decide which ads play on the videos you watch?

Turns out it works a lot like Google and Facebook ads do. Like on other free sites, the advertisers help fund the YouTube experience in return for exposure to ads. You`ll see certain ads over others because of your demographic groups, your interests (which is judged in part by what you search on Google and YouTube) and the content you`ve viewed before, including whether or not you`ve interacted with the advertiser`s videos, ads, or YouTube channel.

YouTube`s algorithms also try to make sure people aren`t overloaded with ads while watching videos -- so it actually sometimes won`t show ads on monetizable videos, even when there`s a demographic match.

Here are the five ad formats you can expect to see on YouTube, and how they work:

A. Display ads, which show up next to the video and only appear only on desktop and laptop computers. The advertiser gets paid when you see or click on the ad, depending on their selection.

Image via YouTube`s Creator Academy

B. Overlay ads, which appear across the bottom 20% of the video window and currently only appears only on desktop and laptop computers. You can X out of the ad at any time.

Image via YouTube`s Creator Academy

C. TrueView in-stream, skippable video ads, which are most common ads. These are the ones you can skip after watching for five seconds. Advertisers can put it before, during (yikes!), or after the video plays, and they get paid only if you watch at least 30 seconds of the clip or to the end of the video ad -- whichever comes first.

Image via YouTube`s Creator Academy

D. Non-skippable video ads, which are those longer, 15-or-more-second ads you see before plays and can`t skip after any period of time, no matter how much you shout at your screen.

Image via YouTube`s Creator Academy

E. Midroll ads, which are ads that are only available for videos over 15 minutes long that are spaced within the video like TV commercials. You need to watch the ad before continuing through the video. How the advertiser gets paid depends on the type of ad: If the midroll is a TrueView ad, you`d have to watch 30 seconds of the end or the entire ad -- whichever is shorter. If it`s a CPM-based ad, you have to watch the entire ad no matter how long it is.

Image Credit: YouTube`s Creator Academy

F. Bumper ads, which are short, non-skippable ads up to six seconds long that play before the video the viewer has selected. Bumper ads are optimized for mobile devices and must be watched in their entirety before viewers can progress to the video they want to view.