Last summer, Boston-based Where, which runs a mobile ad network and location-based recommendation service, opened a development center in Croatia to supplement its 18-person U.S. mobile engineering staff.

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Time magazine, for example, has formed a partnership with Foursquare, a location-based mobile check-in service, for the conventions, in which Time has provided content that users can unlock when they get to certain locations in Tampa and Charlotte.

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In future, more of this experimentation will take place on Facebook, which boasts over 150m mobile users and so ought to be the one network capable of creating a massive, location-based service fast.

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JiWire is a mobile advertising company that places location-based ads, it calls Compass ads, on mobile apps as well as on Wi-fi service websites in places like cafes.

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