Google has begun testing video ads in search results, reports The New York Times.

According to Google's Marissa Mayer, the introduction of video ads to search results stems from knowledge that text ads don't perform well against video search results.

Recently Google debuted "universal search," which includes multimedia items in a query response. Videos now appear more often as results of a search.

Video ads will at first be unobtrusive: a small "+" will indicate the presence of a video that can be expanded. But Google is considering the addition of thumbnails, which would make video more obvious in an ad.

Search-related video ads will augment the cost of placement. But advertisers must pay when the video is viewed, even if the view does not generate a click-through to the advertiser's site.