Interesting article on Mobile Advertising in BusinessWeek that is worth a read.
The article talks about Pandora - a nine-year-old, free online service that lets users design "radio stations" based on their musical preferences. Pandora has become a very popular mobile app as well and advertisers like Best Buy, Dockers, Target, and Nike have started to buy ads on Pandora to experiment with what remains a cheap advertising medium.
"We've reached a tipping point," says Domino's Pizza advertising executive Rob Weisberg. "Marketers, especially consumer brands, have to take mobile seriously now. You have to be where your customer works, lives, and plays."
Pandora mobile advertisers are seeing pretty solid response rates to their ads which bodes well for the medium.