What Is Google Ad Exchange (AdX)? A Guide for AdSense Users

Google Ad Exchange, usually called AdX, is the name AdSense publishers hear most often when they ask how to earn more from the same traffic. It is also one of the most misunderstood products in Google's lineup. This guide explains what Google Ad Exchange is, who buys on it, how it competes for each impression, where it lives, and how a publisher actually gets access. It also covers what does not change when you move, so you can set your expectations before you start.

AdX in one sentence

Google Ad Exchange is a real-time marketplace, used through Google Ad Manager, where advertisers and their buying platforms bid on individual ad impressions on your site, and where you have more control than AdSense gives you over who can buy, at what price and under which deal type.

The buyer-side view of the same marketplace is called Authorized Buyers, which Google describes as "an online, auction-driven marketplace where ad impressions are bought and sold in real time." When people say "Google AdX", they usually mean the publisher side of that marketplace.

If the names Google Ads, AdSense, Ad Manager and Authorized Buyers still blur together, read Google's ad products explained first. It maps every name to its place in the chain.

Who buys on AdX

According to Google, Ad Exchange demand "can come from a number of large third-party ad buyers, including Google Ads and other buyers participating in the real-time bidding exchange, which may include Preferred Deals and Private Auctions."

In practice that means two broad groups:

• Google Ads advertisers, whose campaign budgets can be spent on display ads on publisher sites.
• Other real-time bidding buyers, such as agencies, brands and buying platforms that connect to the exchange and bid impression by impression.

One point is worth knowing up front. Google states that Ad Manager, AdSense and AdMob "all have access to the same premium Authorized Buyers." So AdX is not a secret pool of advertisers that AdSense never sees. The difference lies in how you can sell to those buyers and how their bids compete with other sources you add.

How AdX competes for each impression (dynamic allocation)

In AdSense, Google decides which ad fills a slot and you see the result. In Ad Manager, several sources can compete for the same slot: campaigns you sold directly, Ad Exchange, AdSense, and other networks or exchanges you connect. The feature that makes this work is called dynamic allocation.

Google explains it this way: dynamic allocation lets non-guaranteed demand, such as the Ad Exchange Open Auction and remnant line items, compete in real time with guaranteed demand, impression by impression. When a guaranteed campaign is eligible for an impression, Ad Manager gives it a temporary CPM, which Google calls the "opportunity cost" of not serving it. Ad Exchange or another non-guaranteed source can win that impression only if it pays more than that opportunity cost.

Here is a simple example with no real prices. Say you sold a sponsorship to a local business and it needs a set number of impressions this month. For each visit, Ad Manager works out how important it is to serve that sponsorship right now to stay on track. If an Ad Exchange buyer bids more than that value, the buyer wins this impression and the sponsorship still delivers on later ones. If not, the sponsorship serves. Your guaranteed commitments stay protected, and the exchange can still win when it values the impression more.

If you have no direct campaigns, dynamic allocation still matters, because Ad Exchange can compete against AdSense and other non-guaranteed sources in the same auction.

Ways to buy: Open Auction, Private Auctions, Preferred Deals, Programmatic Guaranteed

AdX supports several ways for buyers to purchase your inventory. Google lists these as the transaction types that count toward Primary Ad Exchange earnings under MCM: Open Auction, Private Auctions, Preferred Deals, Programmatic Guaranteed and Open Bidding.

• Open Auction: any eligible buyer can bid on your impressions in real time. This is the closest to what AdSense does for you today.
• Private Auctions: you invite specific buyers to bid on selected inventory, with minimum floor prices you set.
• Preferred Deals: a buyer gets a first look at your inventory at a fixed price, without being obliged to buy.
• Programmatic Guaranteed: inventory is reserved for one buyer at a negotiated price.
• Open Bidding: other exchanges and yield partners bid server to server and compete with Ad Exchange in the same unified auction.

Most new AdX publishers start with the Open Auction and only add deals later, once buyers show interest or a partner helps set them up. You do not need to use every option for AdX to be useful.

Where AdX lives (inside Google Ad Manager)

Publishers do not log in to a standalone AdX website. Ad Exchange is a demand source within Google Ad Manager, and its features appear inside the Ad Manager interface. Who can see or change Ad Exchange settings is controlled by user role permissions, under "Trafficking and delivery".

Google describes Ad Manager as a platform that "supports multiple ad exchanges and networks, including AdSense, Ad Exchange, third-party networks, and third-party exchanges." So AdX is one source in a bigger toolbox. AdSense itself can be set up inside Ad Manager at the network, ad unit or line item level, and other partners can be added too, so several sources can compete for each impression.

This also means that to use AdX you need to be comfortable with at least basic Ad Manager concepts: ad units, tags, and reports. Many publishers who reach AdX through an MCM partner let the partner handle much of that setup.

How publishers get access (direct or through MCM)

There are two broad ways a publisher ends up with Ad Exchange demand in Ad Manager.

A direct relationship with Google. Some large publishers work with Google directly. Google does not publish a public application form or a list of criteria for this route, so there is nothing concrete to describe beyond the fact that it exists.

Multiple Customer Management (MCM). This is the route most AdSense publishers take. An MCM partner (the "parent") is given permission by you (the "child") to manage your Ad Manager account or your inventory. There are two delegation types:

• Manage Account: the parent works inside your Ad Manager account, excluding billing, and you use your own tags. You can have only one Manage Account parent.
• Manage Inventory: the parent monetizes your delegated inventory from its own network, and you use the parent's tags. You can have up to 15 Manage Inventory parents, though Google's MCM policies say any given piece of child inventory can only be managed, represented or sold by one parent.

The same parent cannot use both types for one child. With Manage Account, Google routes an agreed share of earnings (anywhere from 0 to 100%) to the parent automatically, and the child still completes identity verification with its own documents.

Google's MCM setup steps also say not to enable Ad Exchange until all monetized sites are approved, and to disable AdSense backfill before turning on Ad Exchange. Our guide on how MCM works covers the relationship in detail, and How to Get Google AdX Access compares the routes side by side.

What AdX does not change (policies still apply)

Moving to AdX changes your tools, not your obligations. A few things stay exactly the same:

• Policies. The Google Publisher Policies apply to anyone monetizing with Google ad code. Not following them can lead to ads being restricted or accounts being suspended, whether you are on AdSense, Ad Manager or Ad Exchange.
• Traffic quality. Invalid traffic (clicks or impressions that artificially inflate costs or earnings) remains your responsibility as the publisher. See our invalid traffic guide.
• Your content and audience. The same buyers value the same visitors. If your content is thin or your traffic comes from sources advertisers avoid, AdX will not fix that.
• Verification. Sites still go through review in Ad Manager, and identity verification still applies. Google gives you 45 days to submit identity documents, after which ads stop.

This is why we never promise that AdX will raise your earnings. For some sites the extra control and competition help. For others the result is similar to AdSense. It depends on your inventory.

Next step

AdX is a marketplace inside Ad Manager, and for most AdSense publishers the way in is an MCM partnership. Eligible publishers may receive an MCM invitation through our MCM partner network, subject to Google's policies and site review. If you want to see whether your account and site are ready, check the requirements, then Get AdX access.