SUNNYVALE, California: Yahoo has launched a new online search advertising system incorporating video and images in its paid-for listings, which the company claims increased clickthrough rates by as much as 25% in trials.

Online is forecast to grow by 15% in the US this year, and search is expected to be the major driver of the medium's expansion.

Yahoo's new service, called Rich Ads in Search, has been trialled by advertisers including soft drinks brands Pepsi and SoBe, dog food brand Pedigree and retail chain The Home Depot.

Alongside rich media, advertisers can include company logos or a search box in which consumers can enter information like ZIP codes to link them to information about their nearest store or outlet.

Marketers will be charged a monthly fee for the service, as opposed to the auction system used for search ads, and the system is currently only available to large advertisers and brands.

Karin Blake, senior search manager at ad agency Razorfish, tested the programme for some clients, and said clickthrough rates improved by between 5% and 10%, but argued there was currently no similar service "in the paid search landscape".

Data sourced from New York Times; additional content by WARC staff