The service is based on a technology called “geofencing,” which is provided to O2 by a Califonia based company called Placecast . In 2009, Placecast conducted a trial, under the name of ShopAlerts, three different type of retailers American Eagle Outfitters (clothing for young adults), North Face (Outdoor equipment and apparel), and Sonic (fast-food outlet). Although there may be some overlap between potential customers at these three retailers, plenty of people will fit one category but not the other two. Targeted marketing reduces the likelihood of relevant marketing messages being lost in “junk mail”; that is, customers texts that they know are probably relevant. According to research carried out by Placecast on ShopAlert users , most customers opened the alerts immediately, and 65 percent made a purchase as a result of receiving the text (interestingly, not always a purchase mentioned in the text!).