If I go into a neighborhood convenience store and discover they make homemade soup and a hand crafted sub sandwich at a good price and with great taste I am likely to go back again. They just improved their foot traffic because I plan to come back.
If I see a sign that tells me a roadside diner has the worlds best cup of coffee and I get a cup that tastes a bit like motor oil I will likely refrain from visiting that location again. They have just decreased their potential foot traffic because I will stay away.
Some of the lessons for online business are as follows
Let some things be a surprise. Allow customers to find a few pleasant surprises along the way. With Search Engine Optimization (SEO) it may be hard to keep everything a surprise, but when a visitor finds something they hadnt expected on your site they might want to come back.
Offer a product that exceeds expectations and is a fair value. It doesnt matter if your business is online or brick and mortar people still shop for value and price. Treat your customer fairly and they may come back.
Never promise more than you can deliver. That roadside diner offered something they didnt really...