Short video ads lasting around 30 seconds are going to be tested on 15 sites over the next five weeks.

This might sound really annoying, but it could mean that eventually there will be fewer adverts on the internet.

Advertisers hope the new ads will grab the attention of surfers more than things like pop-ups, so fewer of them will be needed to sell things.

The companies behind the adverts expect the clips to work no matter how quick or slow people's internet connections are.