In the search world, we cal­cu­late click-through-rate (CTR) as clicks divided by impres­sions, and it mea­sures the num­ber of times an ad was clicked ver­sus the num­ber of times it was viewed. This works a bit dif­fer­ently for Face­book. Here, a user can see the same ad mul­ti­ple times per day, which leads to both a true ver­sus unique CTR for that ad.

For exam­ple, assume you and I see the same ad on Face­book 10 times a piece, and at the end of the day, you click on it and I don’t. This would equate to one click on 20 impres­sions, or a CTR of 5%. But, if we were to look at unique CTR, we each saw one ad through­out the day, you clicked, and I didn’t. This would equate to one click on two unique impres­sions, or a CTR of 50%, which is obvi­ously quite different.

Look­ing at this on a larger scale over the course of a week, we see the fol­low­ing trend:

First picture

If we ana­lyze this cam­paign based on true CTR, we might assume a steady trend of clicks to impres­sions. But, if we include the unique CTR in the analy­sis, we see an increas­ing trend in the pro­por­tion of clicks to impres­sions (or user inter­est), which starts to decrease after the third day.

This brings up the next line of ques­tions in regards to ads on Face­book. When does ad fatigue kick in? At what point do we need to refresh ads or images to inter­est the user again? At Effi­cient Fron­tier, we’re cur­rently test­ing these ques­tions and uncov­er­ing some inter­est­ing find­ings, so stay tuned for more on this topic.

Karen Maci­olek

Senior Account Manager





 You make a great point about ad fatigue. I'm noticing a dropoff in interest after 4-5 days.