Use the local free print classifieds to quickly reach your target audience very inexpensively. Running a local ad there will also get your ad online where it will be seen everywhere including in adjoining locations.
Remember that you can reach different audiences in print than online with some overlap, so be sure to advertise in whichever editions are likely to come to your new location.
Here are some sites you should consider:
American Classifieds (Thrifty Nickel)
Look for any other free classifieds in your area and use them. Check to see if there is a local newspaper in the new area. They may have a weekly special mailing they do to all the homes in their area or at least all the subscribers. (Some actually mail every home in their area - this is a cost effective way to get visibility there.)
Next, get that location listed on Google Plus Places
To find out how best to use G+ Local Places join this G+ community https://plus.google.com/communities/100733314294792518208
Use Universal Business Listings to get your locations listed in all the other important directories and quickly added to the databases that feed cell phone directory and GPS systems. This Case Study shows how effectively that can work for you: http://growmap.com/local-search-ubl-case-study/
Share something in print (flyers, business cards) for the new location on the checkout counter of the original locations. This will allow existing customers to spread the word for you in the new area.
If you would like additional information on how to accomplish any of these feel free to contact me.