Google Ads Double-Serving: What to Watch Out For in 2025

In a move that is reshaping some fundamental elements of search advertising, Google has quietly enabled double-serving, allowing advertisers to appear multiple times across different positions on the same search results page (SERP). This significant policy change, introduced without formal announcement (they’ve done a few of those recently!), marks a departure from Google’s long-standing rule of limiting advertisers to one ad per keyword. Indeed, attempting to double-serve has been expressly forbidden by Google for years and would have led to accounts being closed that attempt to get around this rule. Here’s what marketers need to know about this update, its implications, and how to adapt.

Stealth Update: Double-Serving Introduced Quietly, Now Being Scaled Up

After first being discussed by Anthony Higman on LinkedIn in December and followed up by documentation of the test and policy shift by Search Engine Roundtable, Google recently updated its documentation to clarify that it runs separate auctions for each ad location on a SERP. This means advertisers can now win multiple placements across different positions, such as both the top and bottom ad slots. When queried about this, Google claims this system has been in place for years, but the lack of transparency until now has raised concerns among advertisers.

When queried about this change (also in December last year), Ginny Marvin from Google commented “We’re conducting a small experiment testing different ad configurations. We don’t have anything further to share at this time, and there is no action for advertisers to take.” However, it is now clear that this is either becoming a fully fledged product feature, or Google are rapidly expanding the test. Sources at Google have confirmed that from the middle of March 2025, this new feature is being rolled out on a much wider scale and across more markets.

This quiet rollout follows a pattern seen in other recent changes, such as updates to keyword match types, where significant shifts were introduced with minimal communication. Critics argue this approach contradicts Google’s public commitment to openness and raises questions about fairness, especially as the company faces ongoing antitrust scrutiny.

Key Changes to Google Ads

1. Multiple Ad Placements for the Same Advertiser
   Advertisers are no longer restricted to a single ad per keyword. Instead, they can now occupy multiple positions on the same SERP, provided they win separate auctions for each location.
2. Independent Auctions for Each Ad Location
   Google’s updated system runs distinct auctions for different ad placements. For example, ads appearing at the top of the page are selected through a separate process from those at the bottom or in other positions.
3. Performance Metric Shifts
   Advertisers may see changes in key metrics like Top/Absolute Top Impression rates and click-through rates (CTR). These shifts may complicate performance analysis and make it harder to compare current results with historical benchmarks.

Impact: Potential Winners and Losers in the New System

Who benefits?

Large Advertisers: Brands with substantial budgets stand to gain the most from this change. They can compete aggressively in multiple auctions and secure premium placements across the SERP. For example, a retailer could showcase one ad promoting “men’s running shoes” at the top of the page and another highlighting “women’s trail gear” at the bottom.

Niche Advertisers: Businesses operating in highly specialised markets may see less impact due to lower competition for their targeted keywords.

Who faces challenges?

Small Businesses: Smaller advertisers with limited budgets are likely to struggle under this new system. Competing against larger brands that dominate multiple placements could lead to reduced visibility and higher costs per click (CPC). Early reports suggest possible large double-digit % cost increases for some advertisers, although data is still being gathered about the extent of this.

SERP Diversity Concerns: The ability for large brands to occupy multiple slots reduces overall diversity on search results pages. Early industry observations suggest reduced advertiser diversity on competitive terms like ‘cloud storage,’ aligning with Google’s policy shift favoring large advertisers.

Note the word “Potential”

It is important to caveat this article with the knowledge that this is currently very much a test. In the past, Google have rolled out and scaled up tests very quickly. Successful tests have also made it as a product feature quickly as well, but this is not a cast-iron guarantee that the current test will become part and parcel of Google Ads in its current format.

Ways for Advertisers to Adapt

While Google describes this as an “ongoing experiment”, proactive advertisers can adjust strategies now to mitigate risks and capitalise on opportunities.

1. Optimise Budgets
   • Reevaluate budget allocation: Consider splitting funds more distinctly between brand defence campaigns (targeting top slots) and discovery campaigns (targeting lower placements).
   • Use portfolio bid strategies: Automate budget distribution across high-priority placements.
   • Monitor spending closely: Avoid bidding against yourself across multiple auctions (how this is displayed to advertisers within the Google Ads interface may be subject to change here, so keep looking).
2. Refine Ad Messaging
   • Tailor messaging by placement: Where you see it possible to target specific placements in the future, use urgent calls-to-action (e.g., “Shop Now”) for top slots and educational content (e.g., “Compare Features”) for lower ones.
   • Avoid redundancy: Ensure ads appearing in different positions offer distinct value propositions (this is of course dependent on being able to control which ads show in which placements, which is currently not confirmed / guaranteed, so be mindful of this).
   • Comply with policies: Prevent violations of Google’s unfair advantage policy by avoiding repetitive or misleading content. This will be a tricky one for Google to handle moving forward, as there will inevitably be a degree of repetitive content when the same advertisers show multiple times.
3. Track Key Metrics
   Regularly monitor performance metrics that provide insight into how your ads are competing:
   • Impression Share – checking how often your ads are shown relative to competitors.
   • Overlap Rate – highlights whether you’re competing against yourself in multiple auctions (as mentioned above, how this is displayed by Google may change as the test carries on, so keep checking in accounts for how this is displayed).
   • Branded CTR – checking for changes and tracking effectiveness when defending brand terms against competitors.

Transparency Concerns and Antitrust Risks

This test / update comes at a time when Google is under heightened scrutiny from regulators over its dominance in digital advertising markets. Recent antitrust rulings have resulted in billions of dollars in fines globally, adding pressure on Google to ensure fair competition within its ecosystem.

Double-Serving vs. Google’s Unfair Advantage Policy

Google’s own policies prohibit practices that create unfair advantages for certain advertisers. However, double-serving inherently favors large brands with bigger budgets, raising questions about whether this change aligns with those principles.

Concerns about SERP diversity

By enabling large advertisers to dominate multiple placements, Google risks reducing SERP diversity further – a concern already flagged by regulators and industry experts alike. This is really valid – if I’m scrolling down a page and decide not to click on one of the top results, I am often looking for differing points of view or a variety of content, so seeing the same promoted ad multiple times may not be in my best interest as a user, for example.

Likely cost increases in non-Top Google Ads positions

In addition to this, having larger advertisers crowd out lower placements as well will almost certainly lead to an increase in CPCs for non-top placements. Google undoubtedly has access to this information, but to-date has not shared (for obvious reasons) the impact to their bottom line.

What Could Happen Next?

As feedback from advertisers rolls in, Google may refine its approach to address concerns about fairness and competition. Below are purely speculation/ideas, but interesting to think about:

1. Placement Caps: Introduce limits on how many positions a single advertiser can occupy on a SERP.
2. Small Business Protections: Create dedicated auction lanes or budget thresholds for smaller advertisers – we are less convinced by this as it effectively creates a 2-tier system, so is a potential minefield for Google.
3. Enhanced Reporting Tools: Provide more transparency into how multi-placement strategies impact performance metrics like CTR and CPC. This would be our most obvious ask of Google, although we have seen in the past that there is reluctance for Google to hand over data to advertisers to come to their own conclusions. This will likely require a lot of industry lobbying to achieve.
4. Auction Adjustments: Penalise advertisers who already hold multiple placements, or perhaps reward those offering unique value propositions across positions. The idea of having multiple ad locations have higher quality when the propositions and information provided to the searcher are distinct and valuable, may be an attractive route for Google to explore.

Key Questions Asked on Social Media

Q: How does double-serving affect small businesses?
A: We suspect smaller businesses will face increased competition from larger brands dominating SERPs, leading to reduced visibility and higher CPCs. As a guess, by as much as 15–25% for mid-funnel keywords. However, this isn’t just small businesses – some large brands that underinvest in Paid Search would also find themselves impacted this way.

Q: Can competitors hijack my brand terms via double-serving?
A: Yes (they can do this now as well to be clear, but this update will be an added complication). Monitor searches combining your brand name with competitors’ terms (e.g., “Nike vs Adidas”) closely to prevent losing traffic.

Q: Is this change permanent?
A: No…at least, not yet. While Google describes it as experimental, history suggests such updates rarely revert once implemented at scale.

Google Ads Double Serving: Key Takeaways

1. Double-serving offers new opportunities for large brands but creates challenges for smaller businesses struggling with increased competition and costs.
2. Transparency concerns remain high as Google’s quiet rollout raises questions about fairness amid ongoing antitrust scrutiny.
3. Advertisers can make some adaptations and build some new habits now by optimising budgets, refining messaging strategies and closely monitoring performance metrics.
4. Future changes could include placement caps or enhanced tools aimed at leveling the playing field for smaller advertisers.

As Google continues evolving its auction system, staying informed and agile, as always, will be critical for success in this increasingly competitive landscape.