AdWords Callout Extensions How-To: Highlight Offers About Products and Services in Your Ads.
The goal of Callouts is to show valuable information to potential customers before they click your ad. Callouts will also be a factor in Ad Rank. Google suggests using them to draw attention to important product details, or highlight what makes your business different from your competitors.
Callout extensions let you add additional text that shows with your Google search ads, highlighting specific information about your products and services. You can add anything, within their guidelines, to your ads, to boost and supplement your ad within the search results.
Below is an example of what it may look like in the search results:
Callout Text Requirements
Callout Text Length:
The text for each callout must be 25 characters or fewer. For languages that use double-width characters (like Chinese, Japanese, and Korean), the link text must be 12 characters or fewer.
Callout Text Duplication:
We don’t allow duplication or repetition of callout text with other callouts, ad text, or sitelink text within the same ad group, campaign, or at the account-level. Examples of text use that is considered duplication/repetition:
• Your ad text AND ad group, campaign, or account-level callouts include the text “Free shipping.”
• You duplicate one callout at the account level: a) 24/7 customer support b) 24/7 Customer Support.
• No keyword insertion: You can’t use the keyword insertion feature within your callout text.
Create your First Callout.
This is Similar to Sitelinks, Without Needing Links!
It doesn’t cost anything extra to add callouts to your ads; you’ll still pay simply for costs per click.
All callout extensions are created within the ad extensions tab in the View: Callout extensions drop-down menu option. There, you can edit existing callouts or create new ones. Simply add the new callout text, choose your device and scheduling preferences, and hit save.
Callout Extension Tips & Tricks
• Callout extensions are available only for “Search Network Only” and “Search Network with Display Select” campaigns.
• You are not allowed to duplicate text in callouts
• Google will generally show your highest performing and most useful combination of extensions and formats,
• You cannot use dynamic keyword insertion
• Callout text and the content the ad points to must be family-safe and cannot contain adult content.
• You can’t use gimmicky symbols or emoticons in callouts.
• Keep callout text short
Use sentence case
Source: MarlinCS Blog