Revisions for display and messaging, which recommends aspect ratios and banner dimensions, maximum file sizes and file formats among other specs, took six months to revise and refine. The MMA hopes to update all guidelines every six months.

Consensus came fairly easy for the mobile web banner and the text messaging guidelines, but deciding on downloadable content and multimedia messaging service (MMS) took more time and patience to hash out, says MMA president Laura Marriott. "I think that's because we see higher adoption rates and broader consumer reach for web banners and text messages," she says. "We had more debate around downloadable content and MMS because of regional differences."

The downloadable guidelines include graphic file formats for advertising in video games. The MMA recommends that, where the consumer is disrupted by a click-through, ads for applications and games should display before the launch or exit of the application, be queued until the end of the application experience, or avoided altogether.

With guidelines in place consumers, can expect to see more advertisements on mobile phones. Worldwide spending on mobile advertising reached nearly $2.7 billion last year and should hit $4.6 billion in 2008, rising to $19.1 billion by 2012, according to eMarketer. The research firm estimates messaging will account for more than $14 billion of the total $19 billion spent on mobile campaigns by 2012. The United States remains the largest market for mobile advertising, although it lags both Europe and Asia in terms of cell phone sales and use. EMarketer estimates the total U.S. market for mobile advertising will reach $6.5 billion by 2012, up from nearly $1.7 billion this year.

As for the MMA, the 70-member company committee comprising publishers, mobile content providers and agencies is chaired by Madhouse in Asia, Nokia and Vodafone in Europe, and Verizon Wireless and Yahoo in the US.

The MMA has a global mobile advertising committee with five working groups: mobile web, downloadable, text, MMS, and video and television. The group also released a white paper that explains the options and how to buy mobile advertising in order to help companies understand the metrics and available resources.