An ad extension (Google rebranded them "assets") is extra information attached to your ad — extra links, phone numbers, ratings, addresses, images. Google adds them when it thinks they'll improve CTR. They're free to add. They don't always show, but when they do, they take up more screen real estate and push competitors down.
The seven that matter
1. Sitelinks
Extra links under your main ad. "Reviews", "Pricing", "About us", "Contact". Up to 4 show on desktop, 2 on mobile. Highest impact extension — typically lifts CTR 5-15%.
Setup tip: write 6-10 sitelinks so Google has options. Each should describe one specific page on your site, with description text that adds value.
2. Callouts
Short selling points that appear under your ad. "Free shipping," "24/7 support," "Family-owned since 1998." Not clickable. Six characters min, 25 max each.
Setup tip: write 8-10 callouts. Mix offer-based ("$49 first visit"), trust-based ("Licensed & insured"), and convenience-based ("Open weekends").
3. Structured snippets
Lists of features under categories. Pick a category like "Brands," "Services," "Types," and provide values: "Brands: Nike, Adidas, Puma."
Setup tip: pick one or two categories that highlight your range. Don't force-fit if your business doesn't have natural categories.
4. Call extension / call asset
Adds your phone number to the ad. On mobile, it becomes a "tap to call" button. Critical for service businesses. Pair with call tracking — see our guide.
5. Location / business address
Pulls from your Google Business Profile. Shows your address and a map. Critical for any business with a physical location.
6. Image extension
Square images that appear next to or above your search ad. Wildly under-used. Adds visual differentiation in a sea of text-only competitors.
7. Lead form / promotion / app
Niche but useful in specific cases. Lead form extension lets users submit their info directly from the ad. Promotion extension highlights deals ("20% off — ends Sunday"). App extension drives mobile installs.
How to set them up
- Google Ads → Ads & Assets → Assets.
- Click + → pick the asset type.
- Add at the account level so it inherits to all campaigns. Override at campaign or ad-group level when you want a specific call-out.
- Wait 24-48 hours for them to start serving. Google decides which combinations to show on each impression.
Performance reporting
Google Ads → Ads & Assets → Assets → click any asset → see its impressions and CTR. Your top sitelink and top callout will be obvious. Pause the bottom 30% periodically and write replacements.
Meta and Microsoft equivalents
- Microsoft Ads: nearly identical UI to Google — Sitelink Extensions, Callout Extensions, Action Extensions, Call Extensions, Location Extensions, etc.
- Meta: doesn't have "extensions" in the same way, but advantage+ ads, multi-product carousels, and "more options to get in touch" buttons fill similar roles.
- Nextdoor: business profile fields (hours, service area, response time) act as extensions in their feed format.
Common mistakes
- Setting one of each, then forgetting them. Google needs options. Write 8 callouts and 6 sitelinks minimum.
- Generic sitelinks. "Home", "About", "Contact" don't add value. "Read 200 reviews", "See pricing", "Free guide" do.
- Calling them after the fact. Add extensions before launching a campaign. Quality Score takes them into account from day one.