Many of these social media outlets have apps which allow you too check and update social media from a smart phone. One of the features of these apps is the ability to check into a location. Businesses have jumped on this feature as a way to market their business. The person checking into your business has already done the work, they check in and everyone can see that they are there. Others see it, they are interested and may visit. But businesses are taking it to another level. Businesses are starting to give discounts or deals for checking into the place of business. Lets say you check into Red Barn and you get 25% off on Busch Light. Thats a deal one can't pass up! It is a simple, easy way of marketing which pretty much lets the consumer do all of the work.
http://www.thestreet.com/story/11271716/1/how-to-mobilize-your-social-media-marketing.html