Call assets and call-only ads: maximizing phone leads in 2026

Phone leads are among the highest-value conversions Google Ads can generate for service businesses. Someone who calls has already made a decision to engage, moves faster through the sales process, and converts into paying customers at a significantly higher rate than anonymous form submitters. Yet in 2026, the majority of advertisers still underutilise call assets or have never properly tested call-only ads. This article explains exactly what these formats are, when to use them, how to measure call conversions correctly, and how AdBrains AI automates the entire process to deliver structurally better results.

What are call assets in Google Ads?

Call assets, formerly known as call extensions, are supplementary elements added to a standard Search ad. They display a clickable phone number directly beneath or alongside your ad text. On mobile devices, tapping the number opens the phone dialler instantly, allowing users to connect with one action. On desktop, the number is shown as a trust signal without click-to-call functionality.

Call assets can be set at account, campaign, or ad group level. The most efficient approach is campaign-level setup for campaigns specifically targeting phone enquiries. A call asset includes at minimum a phone number, optionally verified through Google's verification process. You can also define display schedules so the number only appears when your team is available to answer.

For Clima-Active.nl, which installs air conditioning systems and heat pumps, call assets are indispensable. Someone searching for "urgent air conditioning installer" on a hot day does not want to navigate a website. They want to call immediately. By attaching call assets specifically to high-intent campaigns, the barrier to contact is reduced to a single tap.

What are call-only ads?

Call-only ads vs. standard Search ads for lead gen

When to choose which format?

Standard Search Ad

• Drives traffic to landing page
• More steps for the user
• Suitable for exploratory searchers
• Conversion via form or chat
• Measured via website conversions
• Flexible for e-com and lead gen

Call-only Ad (AI-driven)Recommended for phone leads

• Direct call action, no landing page
• Shortest path to a high-value lead
• Ideal for urgent or complex services
• Conversion via phone call
• Measured via call conversion tracking
• Maximum ROI on mobile traffic

Call-only ads take this further by removing the landing page entirely. The only action a user can take is to call. The ad displays a headline, two description lines, your business name, and your phone number. It only appears on call-capable devices, primarily smartphones. Every click is effectively a call attempt, making cost-per-click synonymous with cost-per-call.

Call-only ads are best suited to services where urgency or complexity makes a direct call the natural next step. These include:

• Installation services such as air conditioning, heat pumps, and boilers (Clima-Active.nl)
• Financial advisers and mortgage brokers offering personal guidance (LeroyBrouwer.nl)
• Emergency trades such as plumbing and electrical work
• Test-ride requests for high-value products such as the electric folding bikes sold by E-4motion.com
• Legal and medical services requiring immediate consultation

The core strength of call-only ads is that the conversion path is optimised entirely for callers. There is no distraction, no page load delay, and no form to deter high-intent users. The trade-off is that website traffic is not generated, making call conversion tracking the sole measurement mechanism and therefore a critical technical requirement.

Measuring call conversions correctly

Accurate call conversion tracking is the foundation on which Smart Bidding for call campaigns is built. Google Ads provides two primary tracking methods.

The first is Google forwarding numbers. Google dynamically replaces your phone number with a forwarding number that logs calls through the platform. This works natively for call assets and call-only ads without requiring additional website code. You set a minimum call duration threshold in Google Ads, typically 30 to 60 seconds, to qualify a call as a conversion.

The second method is website call tracking via a JavaScript snippet, relevant for call assets on regular Search ads where users still land on the website. A dynamically inserted number on the page is tracked as a conversion when a visitor calls after seeing it. Advertisers who have implemented server-side tracking through a dedicated sGTM setup can enrich these call conversions with first-party data, significantly improving the signal quality fed to Smart Bidding.

The comparison table below summarises the three main measurement approaches:

Setting the correct minimum call duration as your conversion threshold has a direct impact on Smart Bidding performance. A threshold that is too low, such as 10 seconds, causes cancelled or misdirected calls to be counted as conversions, sending misleading signals to the algorithm. A threshold of 30 to 60 seconds filters out most non-qualifying calls and gives Smart Bidding a clean, reliable signal to optimise toward.

The call asset conversion funnel on mobile

Conversion funnel: call asset on mobile

From impression to qualified phone lead (mobile Search benchmarks)

Impressions

Mobile searchers see the ad

Ad clicks

Average mobile CTR for local services

Tap on phone number

More than half of clickers tap the number directly

Qualified call

Calls longer than 60 seconds counted as qualified lead

Every 1,000 impressions yields an average of 1-2 qualified phone leads via call assets

The funnel a mobile user moves through when encountering a call asset demonstrates why this format delivers such high-quality leads. Around 8% of users click through from impressions for local and urgent searches, a healthy CTR for this type of campaign. Of those clickers, more than half tap the phone number directly rather than scrolling further into the website. A significant proportion of those call attempts result in a qualified conversation lasting more than 60 seconds.

What makes this funnel valuable is the quality of the lead at the bottom. Someone who actively calls after seeing an ad has a substantially higher purchase intent than an anonymous visitor who browses a product page. For Clima-Active.nl, every inbound call about an air conditioning quote can be handled directly by a specialist who can assess the situation personally, resulting in a significantly higher close rate than an email enquiry.

Bidding strategies for call campaigns

The right bidding strategy is the difference between a profitable call campaign and a costly one. The most effective options for call-focused campaigns are:

• Target CPA (tCPA): Ideal when you have a clear cost target per phone lead. Smart Bidding adjusts bids so the average cost per call conversion stays within the set target. Requires at least 30 to 50 call conversions per month as learning data.
• Maximize Conversions: The best starting strategy when a new call campaign lacks sufficient data for tCPA. The algorithm learns quickly which users are most likely to call.
• Target ROAS (tROAS): Suitable when call conversions have been assigned an average revenue value based on historical close rates and average deal size.
• Enhanced CPC (eCPC): A manual bidding base with automated adjustments, useful as a transitional setup before full Smart Bidding is viable.

AdBrains always recommends starting new call campaigns on Maximize Conversions and transitioning to tCPA once sufficient conversion volume has been reached. This transition is handled automatically by our strategy-switch system, which detects campaign readiness and executes the switch without manual intervention.

How AdBrains AI automates call campaigns

Managing call assets and call-only ads manually introduces a range of failure points: call schedules that drift out of alignment with business hours, bidding strategies that are never adjusted as data accumulates, call conversion thresholds that are set incorrectly at launch and never revisited, and ad copy that stagnates. AdBrains has built automated solutions for every one of these challenges, running continuously without manual input.

The foundation is our server-side signal enrichment via a proprietary sGTM infrastructure. Call conversions are not recorded as raw call events alone. They are enriched with first-party signals including the keyword that triggered the call, the time of the call, the duration of the conversation, and where available, CRM data indicating whether the call ultimately led to a signed deal. This enriched signal gives Google's Smart Bidding a substantially more accurate picture of which searchers become qualified callers, translating directly into higher ROAS and lower CPA for call campaigns.

Our automated tCPA/tROAS optimisation monitors call conversion volume and quality daily. As soon as a campaign has accumulated enough data, our strategy-switch system automatically transitions from Maximize Conversions to tCPA, calibrated to each client's specific cost targets. For Clima-Active.nl, the CPA target for a phone quote request is managed separately from form enquiries, because the quality and close rate of these two lead types differ structurally.

The RSA improvement system continuously monitors Ad Strength scores across all active ads, including the textual components of call-only ads. Ads with POOR status are automatically rewritten based on performance data and proven best practices, without a campaign manager needing to flag the issue. This keeps strong, relevant ad copy live at all times, maximising call intent in every impression.

Automated search term mining operates across call campaigns as well. Every day, all search terms that generated call conversions are analysed, irrelevant terms are flagged and added as negative keywords, and high-potential new terms are identified for campaign expansion. This ensures call campaign budgets are always directed toward the most relevant, highest-intent queries and never wasted on traffic that does not convert to calls.

Underpinning every automated decision is our multi-agent verification system. Four independent AI agents review each optimisation action before it is executed, preventing errors in one optimisation rule from cascading into a poorly performing campaign. This level of verification is not achievable with manual management or simple automation scripts, and it is a core reason why AdBrains call campaigns consistently outperform industry benchmarks.

Benchmarks and expectations for call campaigns in 2026

Call campaigns: key performance indicators

Benchmarks for well-structured call campaigns in Google Ads (2026)

60%

of all Google Ads clicks happen on mobile

52%

higher purchase intent for callers vs. form submitters

30s

minimum call duration for a qualified call conversion

3x

higher closing rate via phone vs. email

Call campaign performance varies by industry, but the underlying trends are clearly positive. Mobile search traffic continues to grow, and smartphone users demonstrate measurably higher intent than desktop users for local and urgent queries. Advertisers who correctly implement call assets consistently see higher conversion rates on mobile compared to campaigns without them.

For service businesses in sectors such as installation, financial advice, and healthcare, a phone lead closes at an average rate three times higher than a form submission. This makes a higher cost per call conversion entirely justified in most cases, provided the CPA target is benchmarked against actual revenue per closed deal rather than against form-submission CPA.

For E-4motion.com, which sells new electric folding bikes, call assets are used to generate test-ride requests. A customer considering a 2,000-euro folding bike wants to speak with someone who knows the product and can arrange a test ride. Phone contact at this stage of the customer journey significantly increases the likelihood of a completed purchase compared to an impersonal online form.

FAQ: call assets and call-only ads

What is the difference between a call asset and a call-only ad?

A call asset is an addition to an existing Search ad: the phone number appears alongside your regular ad text and link to a landing page. A call-only ad is a standalone ad format with no landing page, where the only action a user can take is to call. Call-only ads are exclusive to call-capable devices, while call assets are also visible on desktop as a non-clickable trust signal.

How do I set up call conversion tracking in Google Ads?

In Google Ads, navigate to Tools and Settings, then Conversions, and select "Phone calls" as the conversion source. Choose between tracking clicks on a phone number in a mobile ad or calls via a forwarding number on your website. Set the minimum call duration you want to count as a conversion, ideally between 30 and 60 seconds. Link this conversion action as a primary conversion to your campaigns so Smart Bidding can actively optimise toward it.

Are call-only ads suitable for e-commerce businesses?

Call-only ads are primarily suited to service businesses and high-value products where personal contact adds clear value. For standard e-commerce with low average order values, call-only ads are rarely cost-effective. For e-commerce businesses like E-4motion.com, where a purchase decision begins with a test ride and personal product advice, call-only ads can be highly effective as a complement to regular Search and Shopping campaigns.

How do I prevent my call campaign from wasting budget outside business hours?

In Google Ads, you can set a display schedule for each call asset, defining the days and hours during which the number is shown. Match this precisely to your opening hours and exclude weekends if your team is unavailable. For call-only ads, set a campaign ad schedule so the entire ad stops serving outside hours when no one is available to answer. This eliminates wasted spend and ensures every caller who reaches you actually speaks with a team member.