The man who trusts men will make fewer mistakes than he who distrusts them. Even the most suspicious cash-only market in a tough neighborhood allows a certain margin of trust. Just opening his doors every morning and continuing to stock the shelves is an act of faith that more people will buy than steal, allowing him a profit.
Online businesses have specific trust issues.
Many customers are suspicious of every web site they visit, expecting misinformation, shallow promises, and possibly even dangers to their privacy from cookies and viruses. The web gains credibility with each passing month. The cost of doing business online is coming down. Maybe even more so- haven't checked the statistics yet today. The number of those online households that make purchases online is growing even faster.