Last fall, Yelp launched check-ins to cater to its mobile audience, and now the company says its Yelp Mobile visitors are a rapidly growing community. The company announced it received more than 3 million unique mobile visitors last month, which speaks to both rising mobile internet usage and the rise of local search.

The company says 35 percent of all searches on Yelp.com came from a mobile app in December 2010. Yelp saw 45 million overall unique visitors at the end of last year, and it boasted 3.2 million unique mobile app users.

What are mobile Yelp users searching for? Yelp says that every other second, a consumer generated directions to a local business or called a nearby store. Plus, every 30 seconds, mobile users uploaded a photo from a Yelp app, indicating that business owners need to attract local visitors with visual mobile content.

Another development that indicates mobile content may impact consumers' decisions about where to shop is mobile search leader Google's recent announcement that users can upload their own photos to Places pages. User-generated content of this nature might help brands boost foot traffic from Google's mobile searchers, as may the new Latitude check-ins the company is offering.