Writing Ads That Convert

Responsive Search Ads: how they actually work

Responsive Search Ads (RSAs) are now the standard Search ad format. Instead of writing one fixed ad, you supply up to 15 headlines and 4 descriptions, and Google's system automatically tests different combinations and shows the ones that perform best for each individual search, learning as it goes.

This means you're writing ingredients, not a single finished ad. Each headline and description should be able to stand on its own next to almost any other headline or description you've submitted — avoid writing headlines that only make sense as a fixed pair. A headline that says "Here's how:" only works if it's paired with the exact headline that set it up, and RSAs give you no control over which two headlines land next to each other in any given impression.

You can pin specific headlines or descriptions to fixed positions if there's legal or brand-mandatory text that must always appear, but pinning too aggressively defeats the purpose of the format — it stops Google from testing combinations freely and tends to produce a worse-performing ad than leaving most assets unpinned.

Headlines and descriptions that earn the click

Strong RSA assets are specific rather than generic. "Affordable Web Design" tells a searcher almost nothing useful; a headline naming a concrete turnaround time or starting price gives them a real reason to click. Aim for genuine variety across your 15 headlines: include your core keyword phrase in a few, a clear benefit or differentiator in others, a concrete offer if you have one, and a call to action ("Get a Free Quote," "Book a Consultation") in a few more. Avoid near-duplicate headlines — Google's combination testing needs real variety to find a genuine winner.

Descriptions have more room to expand on a headline's promise — use them to answer the objection a searcher is likely still holding after reading the headline. If the headline states the service, the description is a good place for the differentiator: years of experience, a guarantee, service area, or what makes the process easier than the alternative.

Ad strength: what it measures, and what it doesn't

Google Ads shows an "Ad strength" rating, from Poor to Excellent, based on the relevance, quantity and diversity of the headlines and descriptions you've provided. It's a useful checklist for whether you've given the system enough raw material to work with — it is not a guarantee of performance. An "Excellent" ad with generic, uninspired copy can still underperform a "Good" ad that is genuinely relevant and specific. Treat the rating as a floor to clear, not a target to chase for its own sake — once you've cleared "Good," further chasing the rating usually means padding with near-duplicate headlines that add volume without adding real variety.

Extensions: free real estate that improves performance

Ad extensions — now labelled "assets" in the Google Ads interface — add extra information underneath your core ad text at no additional cost per impression, and they can meaningfully improve both click-through rate and Ad Rank, since expected impact of extensions is one of its inputs. The core set worth setting up for almost any account:

• Sitelinks — extra links to specific pages (pricing, services, contact, portfolio) shown beneath the main ad.
• Callouts — short non-clickable phrases highlighting selling points, such as "Free Consultation" or "24/7 Support."
• Structured snippets — a labelled list under a preset header (Services, Brands, Types) that previews what you offer.
• Call assets — a phone number or click-to-call button, essential for service businesses where a phone call is a common conversion path.

Set up as many relevant assets as genuinely apply — each one is another chance for the ad to take up more space on the results page, and a larger, more informative ad tends to earn a better click-through rate purely by standing out against competitors running thinner ads.

Matching your copy to the landing page

Every promise made in an ad's headline needs to be visibly kept on the landing page it sends people to — same phrase, same offer, same service. A mismatch between what an ad promises and what the page delivers is one of the fastest ways to waste a click you've already paid for, and it directly damages the landing page experience component of Quality Score. If an ad headline promises "Same-Day AC Repair," the landing page it points to should say exactly that near the top, not bury it three paragraphs into a general services page. Chapter 5 covers this in detail.

• At least 10–15 distinct headlines submitted, not near-duplicates
• Core keyword phrase present in several headlines
• At least one headline with a concrete offer, price, or differentiator
• Sitelinks, callouts and structured snippets all set up
• Call asset added for any business where phone leads matter
• Ad strength at "Good" or above before launch