(initially this was a reply to the discussion on WebHostingTalk in regards to the .ws domain name for web hosting business web site)
Running your company’s web site doesn’t really require .com domain. However, for marketing purposes, .com domain is almost a necessity, since most people are so much used to all domain names ending in .com (unless you are running del.icio.us, but that’s whole another story and you wouldn’t need an advice in such a case). One of our clients is running a web site with .us domain (actually, he’s the only client who has a non-dot-com domain, as far as I know), but he is marketing to a different niche and in a different way.
In the early days of .biz and .info these TLDs were offered at a huge discount, or even for free. A lot of fraudsters, scammers and spammers have grabbed nice looking domains in those zones which led to the common perception of these domains as “knock-offs”, “fakes” or businesses in third-world countries that shouldn’t be trusted. Currently it’s not exactly true, but that’s what we usually hear from prospective clients when choosing domain name for their web sites.
.COM is a must if you are running E-commerce web site. I would also suggest same approach if you are running web hosting business. There are a lot of aftermarket names you can snatch for a very low fee (we also have some hosting domains for sale). If that’s too expensive – your business model must be wrong.