Popularity is the product of two factors: (a) how compelling material you offer, and (b) how easy it is to access it. Host free pirated movies and users will flock to the site, even if it's difficult to use.
Jakob NielsenInadequate use of usability engineering methods in software development projects have been estimated to cost the US economy about $30 billion per year in lost productivity.
Jakob NielsenThe web is the ultimate customer-empowering environment. He or she who clicks the mouse gets to decide everything. It is so easy to go elsewhere; all the competitors in the world are but a mouseclick away.
Jakob Nielsen