Highly recommended - but not always the best bet
It is quite common to find that people will use a particular company because of a recommendation. Word of mouth is the best form of advertising - we trust the advice of people we know.
Quite recently a couple of people told me they needed a job done, and both said that a particular company was recommended to them by a close friend. In the first case the company was hired, as the price was right; however, the company produced terrible work. In the second case a plumbing company was turned away as it charged far too much and suggested that it would take a full day to bleed radiators in a small house!
Many people write glowing testimonials or make recommendations because the company is the best they've used. In some cases it is the first and only company they have ever used for the service required, so they have nothing to compare against. Also, some people have only ever dealt with companies providing low quality work.
Always do some research. Approach multiple companies. Find out what quality of work and service you are going to get, and if the price is within your budget make sure you get a signed contract covering all of your requirements in detail.