If you can measure it, you can improve it. That is the maxim of online testing. Those who test their advertising campaigns can see ROI double, or even triple. Testing will increase conversion rates. There is no such thing as “good enough." You should always be testing and improving your campaigns.



Every element of an online marketing campaign is measurable. Test your PPC ads, landing pages, and email campaigns. Testing results in actionable data that will show up in your bottom line. Split testing and multivariate testing are the two main forms online testing will take.



Split Testing



Split Testing, also known as A/B testing, is the simplest form of testing. Google AdWords, Yahoo Search Marketing, and most providers of email marketing services have split testing capabilities built right into their campaign interfaces.

Split Testing is randomly dividing visitors into two groups and showing each a different version of your PPC ad, landing page, or email. The objective is to see which version performs better in terms of conversion, CTR (click-through-rate), lead generation, or some other target.

Email campaigns are easily tested. Send one version of email to half the leads on your list, and another version to the other half. Use a subset of your list for testing, and then apply the results to the rest of the list. You can use split testing in this way to find the best layout, ad copy, and headlines for you email.



Split Testing an AdWords Campaign



Google AdWords makes split testing of ad copy easy. Simply create two different ads to driving traffic to the same page and see which one gets a higher CTR. It is important to turn off the optimize feature in the AdWords campaign settings so that both ads get an equal number of impressions.

Another way of to AB test with AdWords is to have the same PPC ad go to two different landing pages. This allows you to split test elements in the landing page for conversion or some other performance indicator. Make sure the two pages are significantly different if you use this method. Search engines frown on duplicate data and may penalize you for it.

Although split testing is simple and effective, it also has drawbacks. Number one is that you need thousands of impressions and hundreds of conversions or click-through actions in order to achieve statistical confidence. The other setback is the ability to test only one element at a time. Testing more than one element can take a lot of time and traffic.



Multivariate Testing



Multivariate testing is the testing of more than one element or variable at a time. This form of testing allows you to test several elements at once and find the individual elements that bring the best results, as well as the combination of elements that will give you the best possible outcome. It allows you to find which elements matter and which combinations are strongest in a relatively short amount of time.

Multivariate testing can give you the best bang for your buck, and the testing algorithm automatically determines the best page design for all possible combinations of elements.

Testing at this level requires sophisticated statistical analysis. Unless you are a coder with and advanced math degree from MIT, you are better off using an off the shelf application or provider. Most providers of multivariate testing are proud of their work and cater to enterprises with deep marketing pockets. The exception is the Google Website Optimizer. It provides all the power of these other applications but beats them on price. It’s free.



Conclusion and Resources



Testing takes the guesswork out of marketing campaigns and allows you to make continual refinements that will increase your ROI. Implement a thoughtful testing program and you’ll be amazed at what works and how little things can make a huge difference. But most of all you’ll be amazed at the difference it can make in your bottom line.

See my article on increasing conversion rates with Google Website Optimizer for more testing tips. GrokDotCom has a wealth of information and resources on the topic of online testing. Be sure to see their 7 free Google Website Optimizer resources. Another good testing resource is Marketing Experiments. There you will find online testing case studies and research.