Location-based marketing enables companies to deliver promotional messages directly to a user who is within broadcast range. For example, if you are near a McDonald's, you might receive a mobile promotion for a discounted value meal. If you're driving in your car and approaching a Jiffy Lube, you might receive a digital coupon for an oil change as you approach.
Is location-based marketing an invasion of privacy?
Of course, this is a matter of opinion. My own view is that this is not an invasion of privacy. There are two main reasons for this.
First of all, your physical location at any time is not something that is, in my view, truly private. In my view, anything that someone could find out about you simply by following you around is not a private matter. If marketers were tapping into your phone calls and emails to find out what you were talking to others about (without your consent) that would be an invasion of privacy because you should be able to expect that those things are private. But when you are out in public, you have no reason to expect that your location would be a secret.
Second, you essentially consent to having these messages sent to you. You do so because you make the choice to carry a phone that will receive these messages. This argument becomes even stronger if the firms that carry out such marketing allow you to opt out of receiving these messages. Even if they do not, the fact that you are carrying a phone that constantly transmits your location to everything around it implies that you consent to have that information known and used.
For these reasons, I would argue that this is not an invasion of privacy.