Brands catering to teens should take note that they may reach their audiences through mobile devices more easily than through PCs. Research from the Pew Internet and American Life Project indicates that nearly one-quarter of teens go online exclusively through mobile phones.

The study found that 21 percent of teens who do not otherwise surf the web access the internet via their mobile devices. Nearly half of black teens (44 percent) use their cellphones to go online, as do 35 percent of Hispanic teens and 21 percent of white teens.

Teens with multipurpose phones might be reached through myriad marketing efforts. Twenty-seven percent go on the mobile web for “general purposes” (presumably including search), 23 percent access social networks via their phones and 21 percent check mobile email.

Businesses that engage teens may find new customers. The survey found that one in 10 teens with internet-enabled phone (11 percent) makes purchases directly from their mobile device, though Pew doesn't specify what type of purchases they make.

The survey supports Brafton's earlier finding that teens are increasingly moving toward online shopping. In fact, 15 percent of teen males and 7 percent of teen females say the internet is their favorite way to shop.