Sitelink extensions (now called sitelink assets) are additional links shown beneath your Google ad, each pointing to a different page — Pricing, Features, Contact. Each sitelink has a 25-character title and two optional 35-character description lines, and they expand your ad's size and clickthrough rate at no extra cost per impression.
Sitelinks do three jobs at once. They make your ad physically larger — a top ad with four sitelinks can roughly double its screen footprint, pushing competitors down. They let users jump straight to the page that matches their stage — someone comparing prices clicks "Pricing", someone ready to talk clicks "Contact". And because Google includes the expected impact of assets in Ad Rank, well-made sitelinks raise your auction score before anyone clicks them. Google's own benchmark: adding sitelinks typically lifts CTR by 10–20% on branded queries and a smaller but real amount on generic ones.
The specs: title up to 25 characters; two optional description lines up to 35 characters each. Always write the descriptions — sitelinks with descriptions are eligible for the larger format and look intentional rather than auto-generated. Desktop can show up to 6 sitelinks (formats vary); mobile up to 8 in a swipeable carousel; clicks cost the same as a headline click. You need at least 2 eligible sitelinks for any to show, and each must link to a distinct page — Google disapproves sitelinks pointing at the same content.
What makes a good set: distinct user intents, not four synonyms for your homepage. A SaaS standard set is Pricing / Features / Integrations / Case Studies; a local service uses Services / Reviews / Service Area / Book Online. Write descriptions as micro-ads with concrete facts ("Plans from $19/mo. Cancel anytime.") rather than slogans.
Add sitelinks at account level once, then override per campaign where intent differs. Review their performance under Assets — Google reports clicks on each sitelink, and swapping the weakest one quarterly is cheap optimization.
Ad for a project-management tool. Sitelinks: "Pricing" — "Plans from $19/mo. Cancel anytime." / "Templates" — "50+ free project templates." / "Integrations" — "Slack, GitHub, Google Drive +40 more." / "Book a Demo" — "15-minute walkthrough. No pressure." Each title ≤25 chars, each description ≤35.
At least 4 (so desktop's larger formats are eligible), ideally 6–8 covering distinct intents. Google rotates and picks per auction; more eligible sitelinks give the system better options. A minimum of 2 must be approved for any to show.
No setup cost, and a click on a sitelink is billed like a normal ad click (same CPC mechanics). The added screen size and Ad Rank contribution are effectively free performance.
Common causes: Ad Rank too low (sitelinks show more for top positions), fewer than 2 approved sitelinks, duplicate destination URLs, or policy disapprovals on individual links. Check the Assets table for per-sitelink status.