The .com domain is technically not synonymous with the USA. There is, in fact, the country domain .us available (though few companies actually use it).

IBM is one company that does use the .us domain: http://www.ibm.us.

Most companies view the .com Web site as their US Web site. Take Yahoo!. On this day, July 3rd, you'll find that Yahoo.com uses a special logo in honor of the Fourth of July holiday weekend.

Visit Yahoo! France and China and it's business as usual.

The reason that the .com domain can be so troublesome for companies is that a good percentage of visitors to the .com domain do not reside in the US. The challenge then becomes one of getting these non-US Web visitors to their country-specific Web sites (assuming the company offers them). It's not an easy process, which is probably why I've been doing so much talking about "global gateway" issues lately. And what I'm finding is that successful global gateway strategies vary dramatically between companies.

Yahoo! appears to be perfectly happy using .com for its US home page. So happy, in fact, that it does not even support the .us domain; you can try it yourself: http://www.yahoo.us.