Now there are many different criteria to consider when choosing a Web Design Company. One of which is, what kind of website is it you need?
Depending on whether you want to sell products, just advertise a bricks and mortar business or something radically different, will govern the skill set required of your chosen Web Design Company.
Most Web Design Companies will be able to design a simple site advertising a business but may not be very good at constructing sites that use an eCommerce Solution to sell products online. When looking at the portfolio of each Web Design Company, pay attention to the type of sites they are making. If they have never built a site with an eCommerce Solution, don