Where can I enable header bidding in Ad Manager?

Meenakshi Bansal, AZAD Architects, Barnala

Learn where and how to enable header bidding in Google Ad Manager to increase competition and maximize ad revenue.

🖋 By Meenakshi – AZAD Architects, Barnala

Where can I enable header bidding in Ad Manager?

Header bidding is a powerful technique that allows publishers to increase competition for their ad inventory by allowing multiple demand sources to bid simultaneously before calling the ad server. Google Ad Manager supports header bidding integrations to help publishers maximize revenue and fill rates. 

This blog explains where to enable header bidding within Google Ad Manager, how it works, and best practices for implementation.

Understanding Header Bidding and Its Benefits

Overview of header bidding and why it is essential for modern ad monetization:

🧠 What Is Header Bidding?

• Header bidding is an advanced programmatic advertising technique where multiple demand partners (ad exchanges) bid on ad inventory simultaneously, before the ad server (like Google Ad Manager) makes its decision.

• Unlike the traditional “waterfall” method (where bids are sequential), header bidding allows all bidders to compete at once, increasing competition and potential revenue.

📊 How It Works

1. When a user visits your website, the header bidding code runs before the page loads fully.

2. The code sends bid requests to several demand partners (DSPs or ad networks).

3. All bidders respond with their offers in real time.

4. The highest bid is sent to your ad server (e.g., GAM) for final decision-making and delivery.

💡 Key Benefits of Header Bidding

🔼 1. Higher Ad Revenue

• By inviting multiple bidders at once, header bidding increases competition for your inventory.

• This typically leads to higher CPMs (cost per thousand impressions).

🔍 2. Greater Transparency

• Publishers can see how much each demand partner is bidding.

• Offers more control compared to traditional programmatic setups.

🚀 3. Improved Fill Rates

• With multiple buyers participating, there is a higher chance that all your ad slots will be filled.

⏱ 4. Faster Decision-Making

• Since all bids are collected upfront, there is no delay in sequential ad serving like in waterfall setups.

📌 Why It is Essential Today

• Modern advertisers want real-time competition and better targeting.

• For publishers, header bidding maximizes the value of every impression and gives more control over which partners serve ads.

Where to Enable Header Bidding in Google Ad Manager

Step-by-step guide to accessing header bidding settings and integrations in GAM:

🔧 Important Note:

Google Ad Manager does not offer native header bidding. Instead, it integrates with header bidding setups (like Prebid.js, Amazon TAM, etc.) through key-value targeting and line item configuration.

You implement header bidding outside of GAM (usually in your website’s header), and then pass the winning bid details to GAM using key-values.

✅ Step-by-Step Guide to Integrate Header Bidding with GAM

🧱 Step 1: Set Up Header Bidding on Your Website

• Use a wrapper like Prebid.js.

• Define your ad units and bidders in the Prebid configuration.

• Place the Prebid script in the <head> section of your website to trigger bidding before GAM ad tags run.

🔑 Step 2: Create Key-Values in Google Ad Manager

1. Go to Google Ad Manager Dashboard

2. Navigate to:

📁 Inventory → Key-values

3. Click New key and define:

  • Key (e.g., hb_pb for price bucket, hb_bidder for bidder name)
  • Type: Predefined or Dynamic

4. Save the key-value setup.

📐 Step 3: Configure Line Items for Header Bids

1. Go to Delivery → Line Items

2. Create one line item per price bucket (e.g., ₹1.00, ₹2.00, ₹3.00 etc.)

3. In Add targeting, choose the matching key-values from Step 2.

o Example: hb_pb = 3.00, hb_bidder = appnexus

4. Set the line item type to Price Priority

5. Attach relevant creatives (you can use a blank creative or universal creative)

🔄 Step 4: Pass Winning Bid to GAM

• In your Prebid config, set sendAllBids: false and define the GAM ad slot.

• Use GPT (Google Publisher Tags) to display the ad based on the winning bid.

Example snippet:

googletag.pubads().setTargeting('hb_pb', '3.00');

googletag.pubads().setTargeting('hb_bidder', 'rubicon');

📈 Step 5: Monitor and Optimize

• Go to Reports → Query Tool

• Run custom reports using key-values (like hb_bidder, hb_pb) to evaluate performance.

🧩 Optional Tools:

• Use Prebid Analytics or GAM Reporting to evaluate demand partner performance.

• Consider header bidding partners like:

  • Amazon TAM
  • Index Exchange
  • OpenX
  • Xandr
  • Pubmatic

Setting Up Header Bidding with Supported SSPs and Partners

How to link and configure third-party SSPs and demand partners for header bidding:

🔗 1. Choose Your SSPs and Demand Partners

• Select header bidding-compatible SSPs (Supply-Side Platforms) and demand partners that support Prebid.js or server-side bidding.

• Common SSPs & partners:

  • Amazon TAM (Transparent Ad Marketplace)
  • AppNexus (Xandr)
  • Rubicon Project
  • PubMatic
  • OpenX
  • Index Exchange
  • Magnite

⚙️ 2. Set Up a Header Bidding Wrapper

• Use a wrapper like Prebid.js for client-side bidding or Prebid Server for server-side setups.

• Integrate the wrapper in your site’s <head> section to initiate bidding before your Google Ad Manager (GAM) tags load.

🧩 3. Integrate SSP Bid Adapters

• Download or configure the Prebid.js package with the specific SSP adapters you want to include.

• Each adapter has its own set of parameters (e.g., publisher ID, site ID, placement ID).

• Example configuration for AppNexus:

{
  bidder: 'appnexus',
  params: {
    placementId: '12345678'
  }
}

🔑 4. Configure Key-Value Targeting in GAM

• Go to:

📁 Google Ad Manager → Inventory → Key-values

• Add keys such as:

  • hb_pb (price bucket)
  • hb_bidder (winning bidder name)
  • hb_adid (creative ID)

• These will be used to pass winning bid information from Prebid to GAM.

📐 5. Create Matching Line Items in GAM

• For each expected bid value (e.g., ₹1.00, ₹2.00), create a Price Priority line item.

• Target these line items to match the key-values from the header bidding wrapper.

• Use universal creatives or creatives provided by SSPs.

🔄 6. Link SSPs to GAM via Key-Values

• The header bidding wrapper sends bid data to GPT using:

googletag.pubads().setTargeting('hb_pb', '3.00');

googletag.pubads().setTargeting('hb_bidder', 'openx');

• GAM reads these and serves the correct line item based on the highest bid.

📊 7. Test and Monitor

• Use browser dev tools and tools like Prebid Debug or HeaderBid Expert to test bidding behavior.

• Monitor performance in GAM via:

  • 📊 Reports > Query Tool
  • Filter by custom key-values to see bid volume, win rate, and CPM.

🧠 Pro Tips:

• ✅ Ensure all SSPs have low latency and support your geo-targets.

• ✅ Monitor discrepancies between SSP dashboards and GAM reports.

• ✅ Always follow SSP-specific setup guides for best results.

Best Practices for Managing Header Bidding in GAM

Tips on monitoring performance, avoiding conflicts, and optimizing auctions:

📈 1. Regularly Monitor Performance via Key-Values

• Use Google Ad Manager’s Query Tool to track custom key-values like:

  • hb_pb (price bucket)
  • hb_bidder (winning SSP)

• Analyze:

  • CPM performance per bidder
  • Fill rate comparisons
  • Win rate trends

⚖️ 2. Avoid Line Item Overload

• Do not create unnecessary line items for every possible price point.

• ✅ Use price bucket segmentation (e.g., ₹0.50 increments) to balance precision and manageability.

• Consider automated line item generation tools for Prebid header bidding.

🚨 3. Prevent Conflicts with Direct or Programmatic Deals

• Use priority settings wisely:

o Set header bidding line items as Price Priority (lower than Sponsorship or Programmatic Guaranteed).

• Avoid overlapping targeting between guaranteed deals and header bidding line items.

🧪 4. Test Header Bidding Setup Thoroughly

• Use tools like:

  • Prebid Debugger
  • Chrome DevTools > Network > Ad calls
  • Google Publisher Console (?googfc)

• Test across:

  • Browsers & devices
  • Geo-locations
  • Network speeds

🛠 5. Use a Unified Price Floor Strategy

• Set dynamic price floors using GAM’s Unified Pricing Rules to control bid acceptance thresholds.

• Apply rules per ad unit, device, or geography to maximize yield.

🧰 6. Update Bidders and Adapters Regularly

• Always use the latest version of your Prebid wrapper and SSP adapters to stay compatible with updates and new bid features.

• Monitor SSP documentation for updates on parameters, bid logic, or supported formats.

🔁 7. Rotate and Test Demand Partners

• Periodically test new SSPs and rotate out underperforming ones.

• Compare win rates and net revenue after platform fees.

📊 8. Enable Reporting Transparency

• Include bidder and price bucket dimensions in your GAM reports.

• Share insights with your ad ops team or monetization partners for optimization.

🚀 Pro Tip:

• Consider setting up Prebid Analytics or connecting with platforms like Google AdX, Amazon TAM, or Index Exchange for better reporting, yield optimization, and auction insights.

📌 Thank you!

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Meenakshi Bansal, AZAD Architects, Barnala

Posted by Meenakshi Bansal, AZAD Architects, Barnala