Initially a business directory and review app, Yelp has increasingly found itself drawn into the current battle between the bigger players in the location-based social app genre, the firm announcing it's set to up the heat in this particular contest and expand in 2010.

That's according to Yelp's VP of Global Corporate Communications Vince Sollitto. Up to 300 new jobs are expected to be created as the firm's network launches in more and more urban areas.

"We're almost doubling our workforce, opening a third office and trying to bring Yelp to new markets and new cities, both in America and overseas," Sollitto told San Francisco news network KCBS, the city expected to be the primary site for Yelp's new development.

Sollitto says the company's most recent investment - which saw $25 million pumped in from venture firm Elevation Partners - has been the catalyst for its planned expansion.

 

Increased traffic has also been a factor. Yelp claimed usage of the network has shot up over the course of the last year, its database of reviews having recently hit 9 million.

The app has also extended beyond its initial remit in recent times, however, Yelp having added 'check-in' functionality last month in an effort to compete with social apps such as Foursquare, MyTown and Gowalla - a move TechCrunch claims Foursquare co-founder Denis Crowley described as "shameless" on his personal blog.

KCBS