A parent after my own heart. There are several important lessons about A/B Testing here: Alternate the children so that you eliminate natural differencesAlways declare a control before testing something elseYou must have a knowledge of statistics to do this rightAccurate measurement and tracking are critical
@KISSMetricsYou want to have a high-converting website. You really do. I'm not kidding.
It makes all of your marketing much cheaper by turning more of your paid and organic traffic into sales. It grows your business more efficiently because your visitors are finding what they want. It gets you off of the "more traffic" treadmill so you can focus on providing great products or great services.
Here is another awesome summary of the things you could be doing to make your site convert better.