A number of companies providing the SEO services keep a check on the factors which are important for the ranking of the websites on the SERPs. The fact that the vast majority of visitors do not tread to the second page of SERPs highlights the importance of ranking on the first page. Hence, all the companies vie for that magical place. To meet this end, they would try to figure out what all is liked by the search engines and would work out their efforts in accordance with that. One of these activities is the selection of the keyword- based domain names.
You make a selection of what is the main keyword which best describes your business and then you prefer taking a domain name which carries the same keyword or its variant if the same is not available. Google or any other search engine does not say whether they like the keywords centric domain names and use them as a metric in their ranking calculations. However, all the indicators point to the fact that all the sites using these URLs do rank higher. If the keywords are really competitive and the others are making use of these types of domain names, then there might be an inclination to use the same strategy so that even small leeway is not given to the competitors.
Search engines use some on-site parameters to know what the website is all about. Some of these parameters that are widely assumed to be used by the search engines for knowing about the content of the website are the title tags, meta-tags, header tags and image alt-tags. Many SEO services providers also consider URLs to be one of these criteria to know what the site is meant for. The domain names, if made out of the keywords, are also helpful to the users in defining the purpose of the site by only reading these. Whatever the search engine robots and crawlers tread on to determine the nature of the site, the SEO services providers make it a point to keep those words keywords centric.
There is always a debate whether using the keywords rich domains constitute spamming or not. All indications point to the fact these are not considered to be of spamming nature. There is full freedom to make use of these keywords centric URLs. To what extent are these held to be useful in rankings is another question and the response to it varies from one SEO company to the other. The companies which are conscious of their already existing brand names do not depend on finding the keywords based URLs or domain names. They would go with their names which are commonly known to the public at large. The sheer authority of the site and other ranking parameters could make their site rank higher in SERPs.
While Google seems to favor the keyword-based domain names, it can not be said to be getting undue importance as compared with the other ranking parameters. You can still get your site to rank higher even when you do not make use of this way.