Introduced a few months back, Google’s Instant Preview displays a thumbnail like overview of the search result pages, highlighting the most relevant section as requested in the search query by a user, consequently making finding the right pages an easier task. A magnifying glass like icon at the end of each result when clicked opens up a small thumbnail like window next to the result that displays the actual layout of the web page, highlighting the section that carries the requested term. This allows for a better evaluation of the search result so that a user can pick the web page that suits him without having to open the page.
This feature has now been extended to pay per click ads as well. Starting now, when a user hovers over an ad, a small thumbnail screen is displayed about the ad. This extended feature is being considered as a win-win situation for the consumer and the web advertiser. For the consumer, the miniature overview of the ad page allows for a comparison of different results as delivered in the search result, thereby allowing a user to pick the page that suits him the best. For the advertisers, there is an increased scope for attracting highly targeted traffic; for users will now (probably) have a look at previews first and click on only those ads that look most relevant to them.
For advertisers, Google will not charge clicks on clicks for previews. A click will be registered only when a user lands on your page after clicking on the ad .