Because we're starting with an existing design then customising it, we don't have to go through a lengthy custom design and build process. This option is very attractive for new businesses and those with a limited budget that still want a professional web presence.
Along with the reduced cost, the turn around time is much quicker, quite simply because there's less work to do. And with there being no design stage there's less back and forth showing you concepts and getting them approved.
Take a look at the examples below, this will give you an idea of the level of customisation that can be achieved. You'll notice that the main layout remains the same whereas the colours, images and overall branding changes to suit each company!