YouTube will introduce a way to advertise on videos it hosts.

The ads will show up as an overlay on the bottom 20 per cent of the video, and people will have a choice to click and watch the advertisement, or not. YouTube will work with select partners on the new advertising scheme, and said in a note on its blog that ad revenue will be shared with content owners.

But the company first needs to show that the new advertising scheme actually works.

Four links sent out in a YouTube statement describing the new overlay ads were supposed to provide examples of how they'll look, but the ads failed to appear. It may be that the links were designed to work later Wednesday, but users can give it a try at: Crime Mob - Rock Yo Hips video, which is supposed to run a Warner Album Browser ad; while an ad for 20th Century Fox's The Simpsons is slated for a Madina Lake - House of Cards video; a New Line Cinema's Hairspray running on Ford Models ad is supposed to run on a How to: Create an evening look in minutes video, and a BMW 3-Series Convertible ad is supposed to run on this Killswitch Engage - The Arms of Sorrow video.

YouTube could not be immediately reached regarding the example links. In the YouTube statement containing the example links, the company said the advertising model was the outcome of weeks of testing. The company does not expect the overlay ads to harm the user experience.

YouTube calls the new advertisements InVideo ads, and they are supposed to be relevant to the video they're matched with, as well as entertaining. The video a user originally clicks to view will be paused while the ad plays.

"If you choose not to click on the overlay, it will simply disappear, so that you're in full control of your YouTube experience," the company said in its blog posting.

YouTube asks site viewers to send suggestions on the new system, but the company apparently wants to keep feedback private. Comments are disabled for the ad blog posting, but users can send an email by clicking on the bottom of the posting, where it says: The YouTube Team.