Back in the day, when Google was in its infancy, the search leaders of the time (Yahoo, Altavista, Excite, etc.) cluttered search results with banner ads. In addition to offering a superior algorithm, one of Google’s most alluring early features was the absence of such intrusions. However, this is about to change, at least on a limited basis, according to Saul Hansell of The New York Times.

According to Hansell, Google began testing video ads in search results today. Here’s how the ads are described:

“At first, users will barely notice the change because the videos will not be immediately obvious. Ads with accompanying videos will have a small button with a plus sign.”

However, this will change in time, according to Marissa Mayer of Google, who tells Hansell:

“… The company would explore adding small thumbnail photos to the video ads as well. And a spokesman said the company is considering testing other formats that may include ads with images.”

Mayer’s justification for the move is that since Google has started including images and video in search results, people have stopped clicking on text ads as much. To counter, she thinks adding visual ads will bring people’s eyes back towards them.

It does sound like Google is taking a measured approach towards adding visual ads, and I wouldn’t expect to see run-of-network “Win a Free iPod” ads anytime soon in the search results. With billions of search queries to monetize, it could mean significant revenue in the short-term. And, from a business perspective, Mayer is correct – eyes gravitate towards images, and thus, I assume click-thrus will increase as visual ads become more common in results.

However, this also seems like a significant cultural shift at Google. It’s the end of what was once considered one of Google’s major strengths, and opens the doors for up-and-comers to go back to Google’ s original spartan approach to search.

The user response will be very interesting to watch on this one.