"The thinking is, basically, that having a keyword-rich domain makes that domain more relevant to the topic. That merely having a popular keyword in the domain will help that site, regardless of content, rank on the high volume keyword. So many feel keyword research (admittedly a bit harder these days) will point to winners and losers. Winners are those with a reasonable volume of queries per month, while losers have almost none or none. They feel the content of the site is less important than having a word in the domain, basically..."