BARCELONA: Mobile advertising via cellphones and other handheld devices is heading for a breakthrough in 2007, delegates to the 3GSM World Congress were promised.

Laura Marriot, executive director of the US-headquartered Mobile Marketing Association, told her audience at the mobile communications industry's main event of the year: "Previously, there were not enough of the right phones and fast networks to support good advertising." That, she said, is changing fast.

And several exhibitors at the show claimed the ability to integrate advertising with the mobile phone in a way that respects users' privacy while at the same time bringing in new revenue to offset sagging growth in voice services.

US members of the MBA - including Verizon Wireless and Sprint-Nextel - have agreed guidelines to ensure that phone-owners will see advertising only after "opting in" to receive the messages, usually in return for cheaper or free services. The organization is finalizing similar rules for the European market.

Added Marriott: "Privacy is a big issue, and that has to be solved for mobile advertising to be successful. I don't think people will opt in 24/7, but maybe they will opt in for certain times of day and for certain types of advertising."

However, Arun Sarin, ceo of UK-headquartered Vodafone, warned that an industry technical standard was also key to allow advertisers to sell to many operators at once.

He said: "If we don't work together, our suppliers will see a fragmented medium and a fragmented user base, as opposed to a single valuable medium. We need to seize the moment and work together to help ads move to mobile. It won't happen well if Vodafone does it differently than Orange and T-Mobile."

Data provider Informa Telecoms & Media forecasts that the market for mobile ads will rise to $11.3 billion (€8.63bn; £5.79bn) in 2011 from almost zero two years ago.

Data sourced from International Herald-Tribune; additional content by WARC staff