A/B testing is essentially testing two different versions of the same page to see which one will perform better. Trying to maximize conversions is a tried and tested method to improve a web presence. Going from 1% to 2% increase in conversions is effectively doubling your sales or leads.
Getting started: Tools like CrazyEgg and Google Analytics can help you find where your visitors are getting hung up. Use A/B testing on landing pages as well as other important pages that are not performing at optimal levels to help maximize conversions. Never stop testing, once you’ve done one A/B test do it again with an even newer version.