By Chris Thompson, blogger for About FourSquare

It would be hard to find a social media sector that is enjoying more innovation (and disrupting more marketing plans) than geosocial, affectionately shortened to “geo”. What began to many as a novelty application in which friends shared their whereabouts with each other by “checking in” to different venues by publishing their location data (using a GPS-enabled mobile device) on various geosocial networks. Many of these geo networks have dramatically increased adoption by incorporating “game mechanics” (to increase participation) and offering promotional opportunities to brands/merchants (to increase value). Each network offers its own set of promotional opportunities. Following are several ways marketers may consider incorporating geo networks into their mix.

Foursquare is a digital city guide that delivers tips and recommendations about the places you should visit based on your friends’ suggestions. The social network offers several avenues for marketing your business.

- Specials; There are seven types of specials that can be used to draw in new visitors and encourage customer loyalty for brick-and-mortar businesses. The newbie special rewards customers on their first check-in (e.g., Radio Shack offers a 20% discount) “Check-in specials” reward customers any time they check in (e.g.Chili's offers free chips & salsa). Check-in specials can also reward customers after multiple visits (e.g.Victoria's Secret offers two free items with a $40 purchase on the third check-in). The most frequent visitor of venues listed on Foursquare is dubbed the “Mayor” of that location. Many merchants offer “Mayor specials” to motivate people to visit more frequently and compete for that social status. Mayor specials honor the customer loyalty and engagement (e.g.Radio Shack offers them a 20% discount, as well). Other specials reward groups of customers checking in together, creating a sort of "flash mob."

Radio Shack says their Foursquare specials have been wildly successful, with users spending 350% more than average customers. Customers see alerts about the specials when they check in at nearby venues. Marketers who employ Foursquare’s “specials” service get access to analytics about their venues that show demographic information about the people checking in at their venues.

- Branded Pages; Companies without brick-and-mortar stores can offer branded pages, where they leave "tips" for their followers that will appear within the app when users check in. The primary purpose is engaging users with your brand when they’re using the service. Foursquare doesn't charge for branded pages.

The New York Daily News employs Foursquare as a content distribution channel. The newspaper publishes tips that link to photos from their historical archives. Users can click through to see a photo of the place they're standing from 75 or 100 years ago.

Windows Live Photo Gallery offers tips from respected local photographers for getting the best shots at popular photo locations.

The Travel Channel, MTV and LogoTV offer tips from their stars listing their favorite places to eat, sleep and drink.

- Partner Badges; Companies can offer their own badges (like Mayorships, “badges” are a form of social currency, packaged as a digital collectable) to Foursquare users. Foursquare doesn't give a firm price, but they've said $25,000 per month with a multi-month commitment is a fair estimate. Badges are probably the most sought-after reward for many Foursquare users.

Victoria's Secret offers a badge for checking in to three of their stores or at the "Bombshell Hotspots" where they've left tips on their branded page.

The History Channel offers two badges for checking in at places where they've left tips — one for the US and one for London.

Radio Shack offered a badge for "Holiday Heroes" who checked in at coffee shops, gyms, train stations and Radio Shack stores. The badge was their ticket to an in-store discount.

Taking advantage of Foursquare's "core" badges — Instead of paying for a custom Foursquare badge, some businesses have gotten creative with Foursquare's core badges. AJ Bombers restaurant threw a party where users could earn a staple "I'm on a Boat" badge. They saw a 110% increase in check-ins. Other businesses have hosted "Swarm" parties where users can earn one of the highly desired “Swarm badges” (for 50, 250, 500 or 1,000 people checking in at the same time).

Building on top of the API — Foursquare offers a robust API. Many companies have built Foursquare check-ins, tips and recommendations into their own applications. American Express even built their own application on top of the Foursquare API, where users received money-saving tips, shared the items they purchased and earned badges based on their engagement.

Gowalla lets users collect stamps and other items in their virtual "passport". The concept is helping members remember the important events in their lives — in connection with the places where they occur. Gowalla offers three primary rewards for users, all aimed at increasing brand engagement.

- Stamps; businesses of all sizes can offer special passport stamps to their customers on Gowalla. Disney Parks, for example, have a beautiful set of stamps covering just about every attraction in Disneyland and Walt Disney World.

- Pins; Gowalla's pins are similar to Foursquare's badges. National Geographic offers a pin for checking in at three National Parks and Disney Parks offers them for visiting certain groups of attractions, such as Walt's favorite rides.

- Virtual Items; Gowalla awards items randomly when users check in. Users can collect them, leave them behind for other users to find or swap them with items other users have left behind. NASA, for example, offers items like virtual moon rocks and space shuttles for users checking in at NASA-related facilities and science museums.

Facebook Places is the newest entrant to the geolocation space, but it brings the highest number of users thanks to its immense size. Their service, called Facebook Places, is limited to sharing one’s location with his or her friends and offering check-in deals similar to Foursquare's.

Chipotle occasionally offers a buy-one-get-one-free deal for users checking in on Facebook Places. With Facebook's unique Charity deals, McDonald's offered to donate $1 to the Ronald McDonald House for each user who checked in.

All three services encourage brands to be creative. Marketers are limited only by their imagination.

- McDonald's celebrated Foursquare Day (each April 16 — a play on the 4/4 calendar - four “squared” = 16) by entering anyone who became a McDonald's Mayor that day into a drawing for a free limited-edition T-shirt.

- Alamo Drafthouse Cinema offered a free screening at their theater with the most Facebook Places check-ins.

- Southern Comfort placed a billboard in New Orleans that encouraged Foursquare users to check in to be entered in a contest for a free trip to Mardi Gras.

This information is taken from the Social Media ProBook, which was published by Eloqua & JESS3, with the help of some of the biggest names in social media. The Social Media ProBook is a 42-page guide that features practical guidance from many of the most influential figures in social media marketing. The free e-book is designed to help marketers accelerate and improve the results they realise from their social marketing efforts.

Check out the AboutFoursquare blog, which discusses how marketers can incorporate geosocial into their marketing mix.