Your presumption of "significant traffic is the only sign of success" is laughable. Many, many real world small businesses have limited capacity bound by real world resources and they can have a booming business by a few thousand hits a day. It is exactly these small businesses that need shared hosting to keep the costs low but still be visible. In other words, if I need a carpenter in a small town, and google townname carpenter, it needs to come up but just how many orders can said carpenter take at the same time?