And should you have a problem with an order, the correction becomes more involved than if you used a local outlet. The choice is normally decided by four factors price, convenience, quality and service. You will often find that the same photofinishing company has different prices for the same service in various outlets. The processing is the same. However, a few pennies hardly merit a trip across town.
Quality is important.
Seldom do things go wrong with the processing of negatives. It is in the interpretation or printing process that occasional disappointing results are found. Amateur labs mass produce and print for a high level of acceptable prints. Subtle differences you may have made in your exposures are often cancelled in the printing process. Any lab can have an off night.