Once your account is active, you’ll have the option to create multiple ads that will be displayed for all of the keywords within your ad group. This allows you to test different versions of your ad to see which one receives the highest click-through rate. For example, if you’d like to test which of three title variations works best with your ad, create three ads that have exactly the same description and URL, but have unique titles. By keeping the other two ad elements the same, you’ll be able to tell which variation of the title generated the highest click-through rate. In addition, you can choose to let our systems optimize the display of your ads by automatically shifting impressions to the ad that receives the highest click-through rate.