Looking at AdDuplex stats I always had a suspicion that shorter text ads get more clicks that longer ads. This was pure intuition, but today I set on a mission to either prove or disprove this based on data.

The average length of all 4 lines of the text ads on AdDuplex is 120 characters. Let’s ignore mid-sized ads by excluding ads from 110 to 130 characters. There’s approximately equal number of ads that are longer than 130 characters and shorter than 110. Average CTR for the longer ads is 1.35%. Average CTR for shorter ads is 1.69%. Meaning that shorter ads get 20% more clicks than longer ones.

Now lets look at the ratios based only on the first line of the ad. The one shown in bold on AdDuplex. The average length is 24 chars. Let’s ignore ads in 20-28 range. Ads longer than 28 chars have an average CTR of 1.25%. CTR for ads shorter than 20 chars is 1.49%. Again, ads with shorter first line get 16% more clicks than those trying to fit a lot of text.

This is by no means a very scientific experiment, but it confirms what I suspected for some time – size matters. And in the case of mobile ads – short ad copy wins.

P.S.: btw, you can use Bing Vision in your Mango Windows Phone to translate the text in the image above 😉