Click-through rate is a percentage of people who did not only see the ad but clicked on it as well. You can calculate CTR by dividing total clicks by total impressions.
CTR is important to measure for two main reasons. Firstly, it affects your ad quality and you can get discounts from Google for that. So the more clicks you get, the less pricey advertising becomes. Secondly, you can determine the quality of the ads, test, and optimize for a better return of investment.
High CTR does not necessarily mean that you are performing well though. Many clicks in pay-per-click advertising mean that you spend a lot of money. Therefore, it is better to also consider the conversion rate and check whether your bid is not too high.
However, if you get not many clicks but lots of impressions, you have to work on CTR. The main tips are the following:
- use A/B testing for creatives and texts
- bid on long-tail keywords as well
- use ad extensions
- consider once again whether you are targeting the right audience
- play around with ad placements
- consider ads for mobiles
Also, do not forget that good CTR is different for different industries. Sometimes what you consider low is pretty good across the industry.