• by Mark Walsh  @markfwal, September 23, 2010

A new study by mobile ad network Millennial Media and comScore suggests that a small segment of mobile consumers prefer to shop via mobile rather than other ways.

Among the 8% of wireless subscribers who are mobile retail users, 27% said they had purchased or browsed retail items only through their handsets in the last 30 days as opposed to online or in brick-and-mortar stores. The other 73% had shopped across mobile, online and offline channels. The study was based on a survey of 10,000 "connected" mobile users, or those who have indicated they use their phones for more than talking and texting.

Millennial, not surprisingly, encouraged marketers to boost their holiday ad spending on mobile to reach these mobile-only shoppers. "For advertisers, this means there is a new retail audience that can only be reached through mobile," concluded the company in a blog post. Precisely targeting that group of people is another matter.

The study also found that mobile retail shoppers also tend to be slightly more affluent than average, with nearly 34% making more than $100,000 annually compared to about 27% of all mobile subscribers.

Electronics and clothing were the most popular categories among mobile shoppers, with about 30% of people buying goods in each segment. Those were followed by food (26%), entertainment and airline tickets (21% each), hotel stays and flowers (19% each), automotive and tools (17%), sports/fitness (15%) and car rentals (14%).

New data released by Forrester Research Wednesday, however, suggests that mobile commerce is still the province of a very small fraction of cell phone users. The research firm's annual overview of consumer technology adoption found that only 2% of mobile users buy products through their phones at least monthly and 2% get mobile coupons or promotions. Slightly more -- 5% -- use their devices to research purchases. Forrester's findings were based on a survey of 30,452 adult cell phone owners.

Separately, Millennial's monthly ad report on mobile advertising trends showed no major changes in ad practices from the prior month. More than half of mobile campaigns (57%) were geared toward reaching a broad audience, while 43% were targeted based on demographic, geographic, behavioral and other factors.

Nearly 80% of campaigns drove visitors to a mobile site -- either a marketer's own site or a custom landing page -- while 22% involved some form of expandable rich media. Millennial attributed the emergence of the latter category to new advertisers, including insurance and CPG brands, using rich media elements to promote mobile apps and video content.

The ad network said the U.S. mobile Web audience in August increased slightly to 80 million, and that its reach grew to 72 million, or about 80% of the audience.