Have the product people want and make it easy to buy. I can't count how many times I've seen a company skip "easy" and try to create a web site with custom checkout software and more.
If there is a product, why would you worry over a web server?
Examples of "easy" are Ebay, Amazon (your product on!), GoDaddy.
Our company is looking for a company that optimizes conversions on websites and guides you as to how to redesign your ecommerce site to turn viewers into buyers. Anyone have any recommendations as to good companies that do that well?