If you sell stuff all over the world, or if what you sell is a service like consulting, then why in the world would you care about being listed on the local versions of the big search engines? The better question is, why not? It is easy and free to sign up with Google Local, Yahoo! Local, and Bing Local (though Yahoo! has an optional enhanced service that costs $9.95 per month). And you never know where your next big order or contract might come from. There are probably local businesses that would prefer to work with a local consultant or service provider compared to a remote one.
The process for signing up is similar for Google Local, Yahoo! Local, and Bing Local, though Yahoo! Local is a little more picky about what you have to have on your site and in your application in order to be accepted.
Google Local has the advantage of being the most popular search engine, and Bing has the distinction of having local search refinement that is very good. With a Yahoo! enhanced listing, you get reports detailing how many times your listing showed up and how many times people clicked on it. You could sign up for all three of these within half an hour, and Bing and Google allow you to post photos, coupons, and other goodies with your listing. This is one of the best half-hour investments you could make to benefit your business, and ignoring this could be to your competitor’s advantage.