In November 2010, Google Instant Previews was lauched on Google.com that provides a graphic overview of a search result and highlights the most relevant sections, making finding the right page as quick and easy as flipping through a magazine.
Now, Google launche the "Instant Previews for Ads" to US users. "Starting today, the Instant Previews icon will appear next to ads on Google.com allowing users to preview the ad's landing page. With Instant Previews, your customers are able to quickly preview a page to see if its content matches what they're searching for," informs Google.
By allowing potential customers to preview your site before they arrive, Instant Previews helps you get even more highly-qualified traffic to your site. Even better, Instant Preview clicks are free of charge -- you're only charged if a user clicks through to your actual landing page.
Instant Previews for Ads will be rolling out internationally over the coming weeks.
More Info: Help center
[Source: Inside AdWords blog]