340308c7_al_Bicycle_Dealers_Association__Bicycle_Shops
[Advantages] Safety Some mass-merchants sell unassembled bikes meaning you have to do it yourself (yes, it's "only" a bicycle, but it still requires significant know-how to build it right). Plus, no test rides, tune-ups or safety tests are available. Many buyers eventually bring these bikes to bike shops to be properly assembled or adjusted. [Bicycle Shops] 
Bicycles come in boxes and need to be assembled carefully and properly to be safe, work right and hold up. Bike shop bikes are assembled in-store by experienced mechanics, and each is test ridden to ensure proper function and safety. They are then carefully fit to you at the time of purchase. Test rides, tune-ups and instructions assure safe and great rides.
The Bike Shop Advantage - National Bicycle Dealers Association
Bicycle Shops