Many, many pundits have predicted that this will be the year that location-based apps (and, implicitly, location-based marketing) will hit the mainstream. It's understandable to see why they would think that - people are sharing more and more information on Facebook & Twitter, GPS-enabled smartphones are becoming nearly ubiquitous, and popular location-based games Foursquare and Gowalla are rapidly growing.

Still, I don't believe that location-sharing will become truly mainstream within the next 11 months.  Indeed, I think that most experts and pundits are underestimating the privacy and security concerns that will come to the forefront as location-aware services get more popular.

In my mind, there's a clear distinction between services and applications that use your location to provide information or services and those that use your location for social purposes.

I routinely use the GPS-enabled features of my iPhone to get driving & transit directions, get local showtimes, find nearby restaurants, locate the closest Citibank ATM, Redbox kiosk, or Starbucks location, and more.  I consider myself a pretty "tech savvy" user.

However, when it comes to sharing my location with others - be they friends or folks unknown - I'm much more conservative.  True, I've been playing around with Yelp's new "check-in" feature, and I occasionally mention where I am in a Twitter update, but these are the exceptions - not the norm.  If I, as a tech-savvy user, am so unwilling to share my every movement, why would an average Joe want to?

As a marketer, I see the immense appeal of locational data.  If I know you're near my business, I would love to be able to send you a limited-time deal to get you in the door.  However, as a user, I don't want every business within a 2-mile radius to be sending me special offers - I just want to be able to get offers from my favorite businesses, regardless of my current location.

Therein lies the primary problem of "location-sharing" for me: motivation. What is going to motivate the average American to share their current position with the world?

Foursquare and Gowalla are structured as games, with users unlocking "badges", "mayorships", and "pins" that they can virtually share with friends.  The most active users use the services to stay in touch with friends and meet new people who patronize similar businesses/venues.  In my mind, though, this has a pretty limited appeal - it's like the Dungeons and Dragons community for the 21st-century.

Yelp's "check-in" feature allows reviewers to become recognized as "regulars" of an establishment, which (in theory) will allow those reviews to carry more weight.  However, I don't really care if an individual reviewer is a "regular".  The true value of Yelp isn't in any single review, but in the aggregate of dozens or hundreds of experiences.

As a marketer, I would love it if people wanted to automatically receive offers from local businesses.  But the reality is that this vast majority of Americans want less advertising, not more.  They're not likely to sign on to a platform for the sole purpose of making my job easier.

Additionally, there are are some substantial privacy concerns with publicly sharing one's location. Already, social media-types are advocating against mentioning vacations & trips on Facebook & Twitter, out of concern that doing so puts out a metaphoric "please rob me" sign in front of people's homes.

Furthermore, does the average American even want their friends or coworkers (let alone strangers) to know where they go and what they do at any given time?  Based on the brouhaha surrounding recent Facebook privacy setting changes, I don't believe so.

I am convinced that location-based marketing will get more pervasive as time goes by.  Indeed, I fully expect that my location-enabled apps will begin providing more locally-targeted ads, deals, and offers over time (especially as Google expands its presence in this arena).  Ideally, these additions will provide developers with a source of revenue while providing me with even better service (one can dream, right?).  At the end of the day, though, I'm not sure that persistent location-sharing (a la Foursquare or Gowalla) will ever become truly mainstream - and certainly not in 2010.

Agree?  Disagree?  Let me know in the comments below, or tweet me.

(Images: Mukumbura on Flickr, Mashable)