Foursquare needs to decide how to conquer local before investor interest cools

Foursquare's day of reckoning could be approaching as it doubles down on various efforts to increase its revenue from the free service while investors, possibly suffering from dot-com and mobile fatigue -- have been reluctant to pitch in for an upcoming funding round. The check-in service as of late has been tilting toward local search for restaurants and other businesses, competing with the likes of Yelp and Google, and has raised more than $71 million to date. But venture capitalists' office doors have not been swinging wide open