"If you aren't using tracking URLs with closed-loop analytics, start. Use tracking URLs anytime you're pushing traffic to your site from somewhere else -- email, PPC, a banner ad, or an affiliate network. If you don't know how many leads and customers you got out of that traffic, you have no idea what you're paying for. In addition, you need to create an organizational culture that's receptive to failure. A/B testing is necessary to success -- you'll never improve your metrics over baseline if you don't change a variable and try something new. A marketer can't be afraid of running a test that fails. Instead, failures should be viewed as successes; i.e., now the organization knows more about what works (and what doesn't) than it did before."

- Lucy Orloski