Header Bidding Explained Like You’re Five

Imagine you’re selling an apple.
You could show it to one buyer and accept their price.
Or you could show it to five buyers at once and let them compete to pay more.

That’s header bidding.
It’s a system that lets multiple advertisers bid on your ad space at the same time, before Google Ad Manager decides which ad to serve.

The Problem Before Header Bidding

Before header bidding existed, most publishers used something called the waterfall.

In that setup, ads were offered to one network first.
If that network didn’t buy the impression, it moved to the next, and then the next, until someone took it — usually at a low price.

So even if a top advertiser was willing to pay more, they might never get the chance to bid.
Publishers lost money every single day without realizing it.

How Header Bidding Fixed It

Header bidding flipped that old process upside down.

Now, instead of sending one offer at a time, your website’s header script invites multiple partners to bid all at once.
They all place their bids within a tiny time window (usually under one second).

When the bids come in, your ad server (like Google Ad Manager) compares them and picks the highest one.
That’s why header bidding almost always increases revenue — because it creates competition.

What Actually Happens on Your Page

When a user opens your website, this is what happens in milliseconds:

1. The page starts loading.
2. The header script triggers a bidding request.
3. Each connected SSP or demand partner responds with a bid price.
4. The highest bid is sent to Google Ad Manager.
5. GAM runs its own auction (including AdX or Open Bidding).
6. The top-paying ad is displayed.

All of that happens so fast that users never notice. But behind the scenes, you’ve earned more for the same impression.

Why It Matters to Publishers

Header bidding gives you control.
You’re no longer stuck waiting for one network’s offer. You decide who competes for your inventory.

That means:

• Higher CPMs due to more bidders
• Fairer competition between networks
• More transparency in who’s buying your traffic
• Better fill rate during low-demand hours

For many publishers, header bidding alone raises revenue by 20% or more — without any extra visitors.

Things to Keep in Mind

Header bidding isn’t just about adding as many partners as possible.
Too many bidders can slow your site and reduce performance.

The goal is balance — fast auctions, clean layout, and quality demand.

That’s why most advanced publishers use a wrapper or a managed stack (like PubThrive’s) to handle:

• Timeouts and latency
• Bid tracking
• Partner performance reports

A clean setup keeps your page fast and your auctions competitive.

Header bidding changed the publishing industry because it made things fair again.
Every impression gets a real-time, open fight for the highest price — just the way it should be.

And the best part? It works quietly in the background while you keep creating.