To build long term and sustainable customer base, web sites need to be tested with real visitors to see whether it is able to attract and retain loyal visitors. It is virtually impossible to perceive different practical situations that a customer experiences in ‘Computer Lab’ environment. As a web developer, you already would have so much of knowledge that some mistakes while debugging a site would never be made by you as by users. But a disgruntled user gives rise to frustrated consumers and leads to loss of sales when scaled up to the global level.
Ascertain the use of your site.