[gibbitz]

As they get bigger competing with them becomes harder and harder as their overhead per transaction reduces due to volume. Eventually they become the only choice. I feel like with Amazon this is nearly the case. Many local brick-and-mortar stores that would have existed in the early 200's are non-existent today. Even chains like RadioShack and Circuit City are gone. This leaves the next alternative to be slower and more expensive online stores that struggle to compete.