Just a note: if you plan on taking advantage of the multivariate-testing features offered free as part of the Google Adwords Website Optimizer, you better make sure you have a lot of traffic. Use the following equation to determine how much:

Number of Combinations = (Daily Unique Visitors * Conversion Rate * Days to Run / 15)

This formula assumes that you will need at least 15 conversions on any given variation to make a sound decision. So for a website that wants to run a test for 7 days, and receives 500 uniques a day, with a 5% conversion rate, they could only have a total of 11 variations. This is useful information, as I made the mistake of having about 30x too many variations. This led me to essentially waste my time, and learn almost nothing useful.

Learn from my mistake. Less variations is better unless you have a ton of traffic and a high conversion rate.

If you just don’t get much traffic, you can always just resign yourself to increasing the number of days you are willing to run your test. I personally had to move the test period up to 14 days to get a really good sample of results for the landing page for our CRM software.

Popularity: 22% [?]