Longer headlines have proven to increase Click-Through-Rate (CTR).
For some ads, Google moves description line 1 to the headline and separates them with a hyphen. This creates longer headlines and a better experience for users, because more information is highlighted in the ad.
To improve your chance to have longer headlines:
- Make sure each description line of your ad appears to be a distinct sentence.
- Make sure each description line of your ad ends in proper punctuation (a period or a questions mark).
Note that punctuation varies by country.
Read more about Longer headlines for select ads on Google.