Search advertising looks set to maintain its position as the most popular method of online marketing.

The announcement from IDC comes as the United States' total internet advertising sector is predicted to grow from last year's figure of $16.9 billion (£8.6 billion) to reach $31.3 billion (£15.9 billion) by 2011 - recording a yearly growth of more than 13 per cent.

Although it will still be the market leader within four years' time, search advertising's market share is predicted to drop to 32 per cent as video marketing becomes an increasingly popular option for promoters.

Programme director Karsten Weide said: "Broadband video commercials will experience their breakthrough in the coming years.

"This will create tremendous opportunities, but also threats, for old and new media companies."

She also claimed Google could face a "strategic challenge" as search advertising becomes less popular.

Figures from the Online Marketing Show earlier this week revealed social media and online PR are the two areas of online marketing set for most investment by UK advertisers during the next 12 months, with the techniques replacing mobile advertising and search engine optimisation in terms of popularity.