Google and Yahoo! have made the internet the main medium for advertising via mobile phones, a number of marketing experts have claimed.

Earlier this month the two search engine giants began their "battle for mobile dominance" as by attaching a number of high-profile companies to their mobile search advertising services, reports DM News.

Deepa Maran, manager of technical services at Digital Brand Expression, told the publication: "As mobile devices grow more sophisticated and users get accustomed to their phone being more than just a phone, marketers that don't want to get left in the dust will have to optimise and advertise for mobile."

She added that advertisers should use XHTML code for their websites and ensure content is accessible to mobile users and search engines.

Chief executive of iLoop Mobile Steve Koskie added: "The internet has become the primary medium for marketing and advertising."