Testing websites and campaigns is key to improving performance. A/B testing—trying two versions of a website landing page and comparing how they perform with your target audience—is often used for this, but it only allows you to test one factor at a time. Multivariate testing, on the other hand, enables you to test many changes simultaneously. Evaluating the impact of combinations of factors and variations often reveals significant interaction effects that can have a dramatic impact on your company's conversion goals.
Do you have a hunch about what's working or not working on your website? Test it and see what happens; the results are often surprising.