Location is the single most important aspect of distribution. All other considerations must follow. There is always an ideal location, because it is the common element behind all other factors.
Cost of access is another. There may be fixed costs associated with gaining access to a location.
Proximity to market. This seems at first much like location, but whereas location considers all factors, the proximity to the market considers how quickly one can move goods. If you cannot move product to market easily, you cannot access your market. Sales will suffer. It's also important to be near the people who actually make the decisions to buy and sell-- this may be quite different than where the ideal location for distribution might be.
These are just a few, but you can see how these factors eliminate some possibilities.