Here's the sickening pitch:
You're walking down the street. You pass a Starbucks. Mmm, that Triple Venti Nonfat Latte sure does look delicious, but you've only got three bucks on you. Maybe next time. But wait! You have a new text message -- "Save $1 on any Starbucks coffee" -- score! Maybe that Latte is within your grasp. Welcome to the world of location based mobile advertising.
The reality is more akin to Corporation A buying ads on your mobile network, and if you are within 20 miles of the thing, you get slammed with a dozen "Buy this now!" ads. (And you're also paying for that ad you don't want!)