Publishers deploy bid throttling to tackle programmatic waste

Major publishers including Chegg and the Daily Mail have implemented bid throttling strategies to combat the overwhelming flood of duplicate bid requests that emerged from header bidding adoption. According to industry reports published on July 15, 2025, these techniques allow publishers to regain control over their programmatic ad inventory while reducing page latency and improving monetization efficiency.

The programmatic advertising ecosystem faces an unprecedented challenge from bid duplication. According to data from PubMatic cited in AdExchanger analysis, the supply-side platform processed 56 trillion impressions in Q3 2022, representing a 33% increase from the previous year. This volume averages approximately 7,000 ads for every person on Earth, indicating massive duplication across the ecosystem.

Header bidding adoption created this explosion in duplicate requests. According to Andrew Byrd's analysis in AdMonsters, "The rise of header bidding overloaded the programmatic supply chain with bid requests. So bid throttling emerged as a much-needed detox." Linda Chen, Senior Director of Ad Strategy and Operations at Chegg Inc, explained the disruption: "The rise of header bidding introduced a lot of disruption. Publishers suddenly found themselves exposing all inventory at once and inadvertently competing against themselves multiple times."

The technical mechanics behind this problem are complex. According to Sarah Sluis' investigation in AdExchanger, "Programmatic auctions are creating so many carbon copies of themselves, it's threatening to topple the entire structure of programmatic." When publishers implement header bidding, they simultaneously ping multiple supply-side platforms for each available ad slot. However, these requests often represent the same impression, creating identical bid opportunities that demand-side platforms struggle to differentiate. This duplication has reached extreme levels, with some SSPs sending the same impression multiple times to increase their perceived value.

Summary

Who: Major publishers including Chegg and Daily Mail, alongside DSPs like The Trade Desk and Microsoft Advertising, are implementing bid throttling strategies to manage programmatic advertising inefficiencies.

What: Bid throttling is a strategic response to overwhelming duplicate bid requests created by header bidding adoption. Publishers use these techniques to limit redundant auction activity while protecting premium demand and improving page performance.

When: The issue emerged with widespread header bidding adoption, with current implementations occurring throughout 2025. The AdMonsters analysis was published on July 15, 2025.

Where: The problem affects the global programmatic advertising ecosystem, with specific implementations noted at Chegg and Daily Mail properties across their digital platforms.

Why: Header bidding created massive bid duplication, with PubMatic processing 56 trillion impressions in Q3 2022 alone. This duplication increases infrastructure costs, reduces page loading speeds, and creates inefficient auction dynamics that waste resources for both publishers and advertisers.

Technical implementation challenges

DSPs have attempted to address duplication through traffic shaping technologies that filter incoming bid requests. Will Doherty, VP of inventory development at The Trade Desk, explained the scope of the problem: "One issue we've encountered is that [SSPs] send 30% of the publisher's traffic – the stuff they think is best – and they send it three times."

Microsoft's advertising platform offers DSP partners self-service tools to specify desired inventory types, while using data science to reject malformed requests. However, these filtering mechanisms often remove valuable inventory alongside duplicates, creating additional complications for campaign scaling.

Cloud infrastructure costs drive much of the industry's urgency around solving duplication. The Trade Desk spent $264 million on platform operations during the first nine months of 2023, equivalent to $730,000 daily for server bills and infrastructure maintenance. When EMX filed for bankruptcy, the SSP owed $900,000 to Amazon Web Services for cloud computing costs.

Traffic shaping algorithms rely on historical bidding data to predict which impressions buyers will value. This approach creates a narrowing effect where DSPs see increasingly limited inventory selection. "What winds up happening is that every exchange chooses the same impression because they're basing their decisions on the expected revenue for each impression," said Chris Kane, founder of Jounce Media.

Publisher response strategies

Publishers are developing sophisticated bid throttling approaches to manage this chaos while protecting revenue streams. At Chegg, Chen implements conservative throttling parameters: "At Chegg, we only start throttling when it's clear the inventory isn't going to monetize. If an ad slot gets called 20 or more times with zero bids, we stop making requests and serve content or a house ad instead."

Chen cautioned against aggressive throttling strategies. "I'm not limiting after just five or six no-bids. That's too aggressive." Her approach focuses on data-driven decisions rather than complex modeling: "Things change constantly. A buyer could suddenly value a new ID or campaign type, and if I've already filtered that inventory out, I lose the opportunity."

The Daily Mail pursued in-house development after experimenting with third-party solutions. Jasper Liu, the publisher's senior programmatic yield analyst, explained their rationale: "We experimented with a third-party bid-throttling solution, but the uplift in yield and [user experience] didn't justify the loss in bid volume. So we transitioned to an in-house approach."

The Daily Mail's system conducts rolling A/B tests based on page type, ad format, environment and browser specifications. Their server-side wrapper manages both traffic throttling and demand seat rotation, providing granular control without manual intervention. "We've seen modest but consistent improvements, particularly in reducing page latency and minimizing any impact from bidders that are resource hungry," Liu said.

Inventory control mechanisms

Beyond bid throttling, publishers are implementing inventory throttling to determine which ad slots enter programmatic auctions. "Inventory throttling is deciding what inventory you even want to allow to be bid on," Chen explained. "It's not about limiting the number of bid requests; it's about choosing which pieces of your inventory go to which partners in the first place."

SSPs have increasingly controlled inventory exposure through curated deals and supply-path optimization packages. However, Chen identified limitations in SSP-controlled approaches: "Their algorithms aren't built for individual publishers; they're built for a marketplace. So what's optimal for a massive network might not work for me."

The Daily Mail protects premium demand through selective throttling application. "From our end, throttling applies only to open auction traffic," Liu said. "Deals—PMP, PG and first-look deals—are whitelisted and exempt from throttling, ensuring no impact on high-value or guaranteed campaigns."

Custom monitoring dashboards track demand partner performance across different integration types and time periods. This data informs throttling decisions while maintaining system calibration as demand patterns evolve.

Industry impact analysis

Bid duplication affects campaign scaling capabilities, particularly for niche advertisers and minority-owned publishers. Emily Kennedy, SVP of programmatic partnerships at Dentsu Media US, noted that traffic filtering disproportionately impacts diverse-owned media companies: "Minority-owned publishers and content providers get filtered out because they often don't generate enough bid volume or are forced to use multiple technology connections."

This filtering extends beyond minority-owned properties to any specialized inventory. Auto insurers seeking niche automotive sites may find scaling impossible when traffic shaping removes "medium to low value" users before campaigns can identify valuable audiences.

The volume bias in DSP algorithms compounds these problems. Many DSPs assume publishers with more bid requests represent larger, more valuable properties, even when actual ad slot counts remain identical. This bias incentivizes continued bid duplication despite its inefficiencies.

Market responses and standards

The Trade Desk has promoted Global Placement IDs (GPIDs) as a technical solution for three years, though adoption remains unclear across exchanges and publishers. The company also implemented floor price disregard policies to discourage SSPs from sending identical impressions at different price points.

"If it's done universally, it should have absolutely no impact since there is the same amount of real supply," said Alex Chatfield, head of Microsoft and Netflix ad sales for Microsoft Advertising. "It becomes a game theory problem, where first movers get penalized."

To address this coordination challenge, The Trade Desk developed OpenPath, providing direct publisher connections with deduplicated inventory baselines. "What OpenPath gives us is clarity," Doherty said, enabling the DSP to evaluate all other supply paths against clean inventory samples.

Google has remained notably absent from duplication policy discussions, with VP of global ads Dan Taylor citing the need for industry-wide coordination: "I do think it would be helpful to get to an industry dialogue around what are the right practices here. Right now, I don't think there is an active dialogue."

Industry observers suggest addressing bid duplication requires coordinated standards development. "We need industry standards, and The Trade Desk is the closest we've come to setting those, albeit aligned with their own goals," said Sonja Kristiansen, chief business officer at TripleLift. "It almost needs to be at the IAB level."

Implementation guidance

For publishers considering bid throttling implementation, Chen recommends starting with simple, low-risk approaches. Regional underperformance provides clear throttling opportunities: if bidders consistently underperform in specific regions, exclude those partners from regional inventory. Similarly, format-specific performance issues justify targeted exclusions from video or display auctions.

"You can keep it simple without building out a complex model," Chen said. Advanced throttling solutions are available from multiple vendors, though she advocates conservative approaches given market volatility.

The importance of long-term performance monitoring cannot be overstated. Chen emphasized building learning phases into throttling strategies: "Things are always changing, so I avoid aggressive models. What looks fine today might have very different results over time."

Market observers expect bid throttling adoption to accelerate as publishers seek greater programmatic control. As noted by Ali Reza Amirmostofian in his LinkedIn analysis, "It all points to a bigger shift: Publishers want transparency and control — not just in what gets bought, but how and by whom. It's about protecting premium demand, avoiding buyer fatigue, and designing cleaner, more efficient supply paths." The shift toward curated deals and reduced open auction reliance reflects broader industry trends favoring transparency and efficiency over pure volume metrics.

Key Terms Explained

Header Bidding: A programmatic advertising technique that allows publishers to simultaneously offer their ad inventory to multiple demand sources before making server-side ad calls. This client-side auction mechanism replaced the traditional waterfall method, enabling real-time competition among buyers and potentially increasing publisher revenue. However, header bidding also creates the duplicate bid request problem that necessitates throttling solutions.

Supply-Side Platform (SSP): Technology platforms that help publishers sell their advertising inventory programmatically to multiple buyers simultaneously. SSPs connect to various demand sources and conduct real-time auctions for ad placements. In the context of bid throttling, SSPs often send identical impressions multiple times, creating the duplication problem that publishers seek to control.

Demand-Side Platform (DSP): Software platforms that allow advertisers and agencies to purchase digital advertising inventory across multiple exchanges and publishers through automated bidding. DSPs use algorithms to evaluate bid requests and determine optimal pricing strategies. Traffic shaping technologies within DSPs attempt to filter duplicate impressions but often remove valuable inventory in the process.

Traffic Shaping: A technical process used by DSPs and SSPs to filter and prioritize incoming bid requests based on algorithmic predictions of value and performance. While intended to reduce server costs and improve efficiency, traffic shaping can inadvertently remove valuable inventory and create narrow visibility for buyers, particularly affecting niche publishers and specialized audience targeting.

Queries Per Second (QPS): A measurement of the volume of bid requests processed by advertising technology platforms within a given timeframe. High QPS volumes indicate significant auction activity but also represent substantial infrastructure costs. Publishers use QPS monitoring to identify when bid throttling becomes necessary to manage resource consumption and improve performance.

Supply Path Optimization (SPO): Strategies employed by buyers and sellers to create more efficient routes for programmatic transactions, reducing intermediation and improving transparency. SPO initiatives aim to eliminate redundant auction paths and reduce the number of intermediaries between advertisers and publishers. However, these optimizations often occur without publisher input, prompting the need for publisher-controlled throttling solutions.

Private Marketplace (PMP): Invitation-only programmatic auctions where publishers offer premium inventory to select buyers at predetermined floor prices. PMPs provide publishers with greater control over which advertisers access their inventory while maintaining programmatic efficiency. In throttling implementations, PMP deals typically receive priority treatment and exemption from filtering mechanisms.

Programmatic Guaranteed (PG): Direct programmatic transactions where publishers and advertisers agree on fixed pricing, volume, and targeting parameters without real-time bidding competition. These deals provide inventory security for buyers and revenue predictability for publishers. PG transactions bypass typical throttling mechanisms since they represent pre-negotiated, high-value arrangements.

Global Placement ID (GPID): A standardized identifier proposed by The Trade Desk to help reduce bid duplication by providing unique identification for individual ad placements across multiple SSPs. GPIDs enable DSPs to recognize when different bid requests represent the same advertising opportunity, theoretically reducing unnecessary auction activity and improving marketplace efficiency.

Server-Side Wrapper: Technology infrastructure that conducts header bidding auctions on publisher servers rather than within user browsers. This approach reduces page load times and provides publishers with greater control over auction mechanics, including the ability to implement sophisticated throttling strategies without impacting user experience or requiring client-side modifications.

Timeline

• Q3 2022: PubMatic processes 56 trillion impressions, highlighting duplication scale
• 2017: Magnite acquires nToggle for traffic shaping capabilities
• February 2020: The Trade Desk joins Prebid.org as a leader member
• Three years ago: The Trade Desk begins promoting Global Placement IDs
• January 2024: Tennis Australia taps Magnite for header bidding wrapper services
• July 15, 2025: AdMonsters publishes comprehensive bid throttling analysis
• Current: Daily Mail implements rolling A/B tests for throttling optimization
• Current: Chegg applies 20+ no-bid threshold before throttling activation