Simplicity will help avoid things getting lost in translation. What's more, trying to explain to someone what the little-known tilde character is over the phone was awkward and time consuming. They may try to visit your site from memory. Now you may be a whiz at spelling, but not everyone that visits your site is. If they misspell or otherwise confuse your domain name, they won't be able to access your site.
Simplicity is the rule.
Suppose you find a more lucrative direction for your web site to take, other than what you had originally intended, or want to diversify by adding a variety of related products and services. A good domain name will be broad enough to allow for such diversity. Before you fall in love with a prospective domain name, you've got to find out if it's still available. It's been estimated that domain names are being snatched up at a rate of about a million per year, so they're going fast. If you're serious about Internet marketing, don't procrastinate on getting your own domain name.