When testing sales and marketing leads, consider multivariate testing, which is A/B testing's bigger (and more complicated) counterpart. A multivariate test can compare a much higher number of variables at one time. Generally, multivariate tests can also show more complex information, therefore telling you more about your campaign performance and testing results.
Typically, when embarking on a multivariate test, you need a software solution like Monetate or Optimizely. What do you use multivariate testing for? Well, you can test a combination of design changes, CTA (call-to-action) locations, copy choices, and more. However, this type of testing gets tricky because you have to ensure that your leads see all possible combinations of your asset to properly assign a winner.
Multivariate testing is great for web and landing pages, and you can gain a lot of information on what the lead engages with. But multivariate testing isn't for everyone, because you generally need a large database and a lot of traffic for it to be truly effective. Think of all the possible combinations if you have a landing page and are testing for copy, CTA location, headline, form length, and so on. You can literally vary thousands of things, and often more.