2. Don't Ignore Other Search Engines

Don’t ignore Yahoo or any of the other smaller search engines. Yahoo results can be responsible for sending you a steady stream of targeted traffic. Make sure you list your site with Yahoo and check your keywords and phrases on their search engines.

These numbers are taken directly from Google Analytics for one of my new sites:

Of the searches from Search Engines, traffic is coming in from Yahoo, Google, Ask and Live in order of traffic received.

So make sure you submit your site to as many search engines as you can.