Clif Bar just launched a marketing campaign via Twitter in which it asked fans to send geo-tagged tweets from parks, beaches, or hiking trails to receive a coupon for a free Clif bar and the chance to win other prizes.

Could this be a clever way to use Twitter's limited geo-location capabilities? 

Twitter does not yet let advertisers target specific locations. A food advertiser can't, for example, target users in a specific restaurant. But the reverse--a company asking fans to voluntarily tweet their location for prizes--is a somewhat novel strategy. It does, however, require some extra labor on Clif Bar's part. The staff will screen each geo-tagged tweet, directed at @CLIFMojoGo, to try to verify that it comes from somewhere outside. Some snags so far: Even Twitter mentions not intended to score a free snack get a response.

MojoGo will run through September 3, and depending on overall results, a company spokesperson said that Clif might decide to use geo-tagging similarly in bigger ways over the next year.

Twitter just recently announced it will allow businesses to utilize broad geographic targeting to send tweets only to followers in a specific region. A company with a broad geographic reach will be able to tailor Promoted Tweets by location (for example, only to New York City-based users).

Using GPS data to target consumers has been a hot topic as of late. Foursquare recently rolled out updates to allow businesses to send messages to users located nearby.