Good question Sandy.

There is much discussion in the industry about this. When you create ads, do you do it for the end user, the search engine or both. Many 'Eye tracking' tests have been done by the engines, especially Google, to see what factors make the Ads more 'clickable'. There findings were that having the keyword(s) in the Ad helped and espcially in the blue title. They also found that highlighting the keyword(s) in bold, made them more so.

In terms of our approach, all sectors are be different and will require different techniques when producing the ads. You need to continually test the adverts in campaigns as in the classic A - B test. Always try to start with at least 2 ads. One should eventually prove to be more attractive. Take this Ad and use it to create a new ad, even if changing one element of the ad, compare the performance to the existing ads.

This 'challenger ad' may prove to be better still - if so, change another element of the ad. If not, then go back a step and introduce a completely new ad, use the click through rate metric to measure the performance.

Of course, you can use the 'Optimise Ad serving' to let Google display the best responded ads more often.

Have you anything you'd like to test specifically?