Just to add another couple to that list Scott linked: wellbeing.com is owned by boots, house.co.uk is owned by British Gas.
Keyword domains can carry natural traffic with them. People have a habit of typing straight into the browser's address bar what they are looking for genericwords.co.uk. Essentially free advertising if you will. However, most of the companies i've seen using them (like those mentioned above) actually redirect to the company's branded website rather than make a business based off the name.
You can also get an idea of how popular specific keywords/combinations are using googles keyword tool:
https://adwords.google.co.uk/select/KeywordToolExternal The comment on Amazon above is partially true, it isn't a word directly associated with e-commerce. But I'm pretty sure the name was coined off the original business plan, an analogy between the number of products they will sell and the number of species of life in the amazon. But single dictionary words like amazon have the advantage, people tend to be able to spell them correctly first time.
Also, if you plan on advertising the domain name, using hyphens between generic-words can mean you miss out of potential traffic. If say you do a radio advertisement, people may assume that there are no hyphens and simply type genericwords versus the real generic-words domain that you registered.