Location-based mobile alerts have led a third of women 18 to 34 to visit a store, according to a recent survey. And 27 percent of that demographic said that mobile messages have impacted their decision to buy in a physical store. The poll, conducted from May 17 to May 19, surveyed 2,046 U.S. adults 18 and older, including 1,710 who own a cell phone and/or a smartphone. It was conducted by Harris Interactive and commissioned by location-based ad company Placecast. It studied opt-in mobile marketing messages only.