I would like to use the same keywords as "control" and determine if one ad is yielding a better CTR than another.
Is it even possible to do test this simultaneously, or is the only way to test one for a period of time and the other for another period?
I understand that when you create more than one ad for a AdGroup, AdWords selects the ads to display randomly or alternately. Can anyone verify this?
Thanks in advance
On the campaign page under edit campaign settings, there is a check box (number 4) marked "Automatically optimize ad serving for my ads." By default this is left on, meaning that your ads will face a darwinian struggle against one another, with the most effective ads (the ones with the highest CTR) being shown more often.
While this is useful for most people, you'll probably want to turn it off for the purposes of testing. This way, the ads will attempt to show themselves as evenly as possible.
While you should get even rotation most of the time, some factors prevent ads from showing evenly when the checkbox is off. Probably the most common is that not all ads have been approved for display on Google's extended network (search sites like Ask Jeeves and AOL, plus content sites like about.com).
I would suggest that, in your test period, you uncheck the search network and content network boxes. This lets the ads run only on Google's site, which means one less variable to worry about. After the trial has run to your satisfaction, you can turn the search network (and possibly the content network) back on, and (if you want) you can turn optimization back on also.
Hope this helps. :)
