"In
marketing, product differentiation (also known simply as
"differentiation") is the process of distinguishing the differences
of a product or offering from others, to make it more attractive to
a particular target market. This involves differentiating it from
competitors' products as well as one's own product offerings." --
wikipedia.com. Effective product and/or website
differentiation can mean the difference between a successful website
and an unsuccessful one.
Here's
a list with more information about Differentiation. Check it out.