From the BBC:

> With thousands of products and services to choose from, ease of use is still a bonus factor rather than a norm and those that possess this elusive quality often go on to dominate markets.

> Google, Amazon and eBay are successful brands not just because of their financial models but the ease with which their users are able to achieve their goals on these sites, be they searching, buying or selling.

http://news.bbc.co.uk/1/hi/magazine/4393468.stm