Google Ads Descriptions: Sentence Case or Title Case?
By Cody See on November 16, 2018 in Digital Marketing
"Capitalize the first letter of every word, except for the little ones."
"It increases clickthrough rate."
That's what I was taught in early 2015.
Now the latest article I could find on writing text ads in title case vs. sentence case was published in 2014. Recent articles reference posts as far back as 2006. In 2006 I was a sophomore in high school and Razr phones were cool. Things have changed.
We went from standard text ads to expanded text ads. Then Google added a third headline and second description line to the expanded text ads. (So, expanded-expanded text ads? Extra expanded text ads? 2X-panded text ads?)
Now we're writing text ads that look like this:
Based on studies from when they looked like this:
And I thought we were past due to test again: Should you write text ad descriptions in title case or sentence case?
This test included 12 ad variations (24 in total — 12 title case and 12 sentence case) and ran nationwide for a total of 40 days.
Before we get to the data I want to make a couple of things clear. The first is that all other ad attributes were equal. We only tested case differences in description lines one and two. Visualized, here’s what I mean.
Second, now that Google only offers two choices when it comes to ad rotation, we chose "do not optimize" (rotate ads indefinitely).
Now, let's get to the data.
Here's what we learned.
1. Clickthrough rate is still higher for descriptions written in title case.
It's true. On average, we found that clickthrough rate is 8 percent higher when text ads are written with title case descriptions instead of sentence case descriptions. This varied from ad to ad though, and it's worth noting that 5 out of 12 ads saw a higher CTR with a sentence case description.
2. Conversion rate is higher for title case descriptions too.
Across all ads, we noticed a 10 percent higher conversion rate for descriptions written in title case. The difference was the most pronounced on mobile devices, where the conversion rate for title case descriptions was 17 percent higher than those in sentence case.
There's an important caveat to note here: On computers, sentence case descriptions performed slightly better — 2 percent better — than their title case counterparts.
3. Average CPCs vary significantly depending on the capitalization of descriptions.
This was the most surprising part of the split test.
The average cost per click changed based on whether or not descriptions were capitalized — and by no small amount. The differences were huge.
We found that average CPCs varied from 6 percent all the way up to 34 percent for the same ads. Out of the 12 total ads, 5 ads had higher average CPCs for title case descriptions, and 7 ads had higher average CPCs for sentence case descriptions.
But across the board, we found that average CPCs were 13 percent higher with ad descriptions written in title case. However, since more ads with sentence case descriptions experienced higher CPCs (7 compared to 5), this was due to title case ads experiencing more volume (i.e. more clicks) and skewing the data.
4. Cost Per Acquisition was slightly better for ads written with sentence case descriptions.
Even though CTR and conversion rate were both higher for title case descriptions, the lower average CPC caused a 3 percent lower overall CPA for ads written with sentence case descriptions. Broken out by device type, the difference on mobile was essentially null, 4 percent for tablets, and 9 percent for computers.
Keep in mind that more volume went to favor title case descriptions with higher CPCs, and that would skew our results here.
Some Answers, but More Questions
I'll continue to write most text ads with title case descriptions by default, but will think twice for computer-only campaigns. Beyond that, this test seemed to generate more questions than answers.
Why do users convert better with sentence case ad descriptions on desktop but title case ad descriptions on mobile? Why does the average cost per click change so dramatically with such a small change to ad stylization practices? Why do SEOs write meta descriptions in sentence case if title case descriptions for text ads increase CTR?
I don't know, but I'd like to know your thoughts and what you've seen if you've run similar tests. (Please comment below)