Choose a domain name that is simple and obvious or simple and memorable is not enough. Most search engines still rely on your title tag to narrow down their searches.
If you are a bookkeeper and your company is called called Marrick Pty Ltd (or whatever) try to obtain bookkeeping-sydney.com.au as your domain name. That way, your site might have a better chance to be found by a prospect who is searching for a bookkeeper in Sydney Australia..
Also, the simplest and memorable strategy is to use your domain name to describe what you do. Therefore, once prospects have found your site through a search engine, typing in a domain name thet describes what you do (ie. sydney-bookkeeping.net.au) will reinforce the ways you can help them.
Place the same keywords in the Title tag
While they are many ways to improve your use of keywords on your web pages, you can boost your ranking in some minor search engines simply by placing your keywords (the same keyword you've been using in your URL) in your page title tag,
your meta description tag and 4 to 6 times in the text on your page. Make sure to use them in normal, well-written sentences.
for more information about domain names