The CTR or Click Through Rate of an ad such as an AdWords ad is a numerical way of expressing how effective it is at attracting clicks. The CTR is usually shown as a percentage and represents the number of clicks that the link or ad has generated per 100 displays.
So for an AdWords ad with a Click Through Rate of 3%, for every 100 times it is displayed it will get clicked on 3 times.
In practice CTRs jump around and particularly with Pay Per Click advertising the CTR will depend very much on where your ad ranks on the page with the top ranking ads usually getting the biggest share of the clicks.
If you want your link or ad to have a high click through rate in the search results pages you need to make sure it is as relevant as possible to the people who are seeing it. You also need to use effective copywriting techniques to attract the click in the first place. One such technique is called Dynamic Keyword Insertion.
In Google’s AdWords system there are some advantages of writing ads that get a high click through rate. The greatest of these is that you can let your ad ranking drop a little by bidding less whilst maintaining high levels of traffic.
A question a lot of people ask about AdWords CTR is what is a good click through rate. The answer will depend on the ranking of the ad and how many advertisers are competing for clicks for your chosen keyword. As a guideline you should aim for 2% or above. A very well-crafted ad in a niche where there is little competition can easily attract a CTR of over 30%.
If you are hosting AdSense ads on your site you will usually get a click through rate lower than this. Similarly, if you are running your own AdWords ads and using Google’s Content Network, you are likely to experience CTRs well under 1%.
For LinkedIn ads, click through rates tend to be lower still and at the moment it can be quite hard to get one higher than 0.005%.