One of the key features of Google AdWords is that you can constantly test elements of your campaign to improve it. And should be. In the past, marketers would test direct marketing campaigns to see which mailings had the biggest response. Unfortunately, it would take months to test various elements of a campaign, if not longer. With Google AdWords you can test elements much quicker and in the process improve your conversion.

A/B testing is in effect, putting two variations on elements of your campaigns to see which version performs better. It could be something as large as competing offers and something as small as testing out different words in text ad.

Here are some elements to test in an AdWords campaign

Testing the words used in text ads – there are only 25 characters in the text link of an ad and just 35 characters each in the two descriptive lines. This isn’t a lot, so each word is crucial to your ad. Always run at least two ads in an ad group, but not many more (then you won't h ave accurate data). Try not only testing the words being used, but also the punctuation. Let the ads run concurrently for a period of time then tweak the one with the lower click through rate. If it eventually overtakes the better ad, then begin tweaking that one.

Testing the site links used with your text ads – site links are proving to be very effective for getting prospects to click on an ad and you should test what site links you use. And the words you use to describe them.

Elements of the Landing Page/Pages – Ideally you want to be able to have more than one landing page so that you can test elements here, as well. Be careful not to test too many elements at once, however, or you’ll lose. Here are just some elements of a page to test:

•The Headline on the Page

•The content of the page, including how much or how little text to have

•The graphics on the page, not just varying pictures, but also the size of the images.

•The colors on the page, from the colors used in fonts to the background.

•The layout of the page

•Having a navigation bar on the page or not

Tweaking the Contact Form – in most cases you want your visitors to perform an action and for some its simply to make a call. In the majority of cases, however, a form is used to capture information about your visitor.  Test not only how many form fields to have, but also the color and text used in the button they click to submit the form.

The smallest element of a campaign can have a surprising amount of impact on a campaign. I’ve seen a period being replaced by an exclamation point have a dramatic impact on click through rates in an ad. So don’t discount anything.

If you’re having an agency doing your campaign and they only seem to be making minimal changes to your ads, don’t assume they’re simply doing busy work. Hopefully there’s a method to their madness. I’d be more concerned if they weren’t doing anything.