Like other companies, Tesla runs showrooms, but those showrooms aren't just for show.
In addition to providing test-drives and customer service, they're also repair shops and charging stations for Tesla owners. Most dealerships have a repair shop, but it is closed off from the rest of the store.
Musk compares the Tesla dealership to a mixture of Apple, Starbucks, and a "good restaurant," because "the Tesla Motors workshop will be out front and on display."
While most dealerships will include a repair shop, none of them also double as gas stations, which means that after buying a Tesla, you can return to the showroom and recharge your car.