Know-How Exchange : Research/Metrics

the best location would be where people would normally go for shopping - shopping centres, shopping malls, where other service providers are located. To make it convenient for your customers.
It also can be a local shop around other shops, in a mini shopping centre.
Main rule - think about your customers first.

First, identify the demographic of who your customer is likely to be. Then, find where your customer generally lives/shops, and position your store in their general shopping corridor.

You will also want to take into consideration the surrounding stores, and how strong the competition might be in the potential area. You'll need to consider not only stand-alone cell phone service stores, but also some big box retailers that sell this type of service as well. If you can, try to get a feel for the amount of traffic in those places who are buying that service. You may have a large market potential, but you also need to understand how much of the potential is currently untapped.