A/B测试：实现方法
http://oldj.net/article/AB-Testing-basic-concept/
A/B测试：实现方法http://oldj.net/article/AB-Testing-method/
http://www.maxymiser.com/resources/ab-testing
http://mailchimp.com/features/ab-split-testing/
http://oldj.net/article/AB-Testing-basic-concept/
A/B测试：实现方法http://oldj.net/article/AB-Testing-method/
http://www.maxymiser.com/resources/ab-testing
http://mailchimp.com/features/ab-split-testing/
