Cross exchange deals: running one site list on several exchanges
Part of Curated deals and PMPs
The short answer
One approved site list can run as separate deals on several exchanges, each with its own deal ID. Each exchange sells only the sites that authorize it, so the deals cover different subsets. Give each site a preferred exchange, cap frequency across the deal line items, update each deal from one list version, and report by site and exchange.
Key takeaways
- A deal ID belongs to one exchange, so a list on three exchanges is three deals with three IDs and three site subsets.
- When a site offers one ad opportunity to several exchanges, the publisher's ad server shows one winner, but the buyer's bids can compete with each other.
- Synced and manually entered deals behave differently in the buying platform, so a list change has to be pushed to each seller and confirmed.
- Uneven delivery is expected, because sites, floors, formats and priority differ by exchange; the troubleshooter shows which stage loses volume.
Can one site list run as deals on several exchanges?
Yes. Display & Video 360's exchange guide (opens in a new tab) says the platform "allows you to bid and buy inventory from publishers through multiple ad exchanges." What does not carry across is the deal itself. A deal is set up on one exchange, and in Display & Video 360 a manually entered deal records its ID and its exchange, and the inventory source guide (opens in a new tab) says both "cannot be changed once saved." One list on three exchanges therefore means three deals.
The three deals will not hold the same sites. An exchange can sell a site only if the site's ads.txt authorizes the exchange's seller account, directly or as a reseller, as the ads.txt specification (opens in a new tab) defines. A list of 60 approved sites may yield 52 sellable sites on one exchange, 37 on another and 18 on a third. Plan with the subsets, not the master count.
| Item | What to record | Why it matters |
|---|---|---|
| Exchange and deal ID | Exactly as saved in the buying platform | Neither can be edited after saving in Display & Video 360 |
| Seller of record | The publisher, sales house or curator that created the deal | List changes go to this company |
| List version | The version number of the master list the deal was built from | Shows which deals are behind after a change |
| Site subset | The sites this exchange can sell, with direct or reseller per site | Explains coverage and delivery gaps |
| Sync status | Synced from the exchange or entered by hand | Decides whether seller changes appear on their own |
How do you avoid buying the same impression twice?
A single ad opportunity can reach the buyer through more than one exchange. With header bidding, Prebid's introduction (opens in a new tab) explains that "The header bidding code calls out to a set of demand partners asking for bids," and that "The ad server will still determine the final winner for each ad unit." One ad is shown for that opportunity. The risk for a cross exchange buyer is not paying twice for one ad, but bidding against itself on two paths and letting frequency run past the plan.
Requests can be linked when exchanges pass the right field. The OpenRTB 2.6 specification (opens in a new tab) defines Source.tid as a "Transaction ID that must be common across all participants in this bid request (e.g., potentially multiple exchanges)," but marks it recommended, not required. Inside one exchange, Google's flattened bid requests page (opens in a new tab) says the google_query_id "will be the same across all flattened requests" and that when two callouts are for a single impression, "only one can win."
Five ways to stop deals competing with each other
- Give each site a preferred exchange. Choose the exchange where the site sells as DIRECT, or the path the buyer's supply rules prefer, and mark it in the master list.
- Decide what the other deals do with that site. Either ask the other sellers to drop it from their deals, or keep it as a backup path and accept that bids may meet.
- Cap frequency above the deals. Display & Video 360's frequency cap guide (opens in a new tab) says an insertion order cap "Sets the frequency cap for all line items under that insertion order," so put the deal line items in one insertion order and cap it there.
- Keep one line item per deal. A separate line item for each exchange deal keeps bids, floors and delivery readable path by path.
- Check sampled logs for repeated tid values. Where exchanges send tid, count opportunities that arrived through more than one deal.
How do you keep site lists in sync across deals?
Keep one master list, with a version number, and treat each deal as a copy that must be updated from it. The buying platform does not update deals for the buyer. Display & Video 360's synced deals page (opens in a new tab) says deals from exchanges that integrate through the Seller API "will automatically update with the exchange's latest details," while "Deals that you manually create by adding a deal ID won't be automatically synced." Even a synced deal reflects what the seller changed, not what the buyer asked for.
The buyer can hold the list on its own side too. Display & Video 360 channels (opens in a new tab) are "custom groups of related websites or apps," targeted through Apps and URLs in line items, with up to 65,000 websites or apps per channel. A channel built from the master list and applied to each deal line item keeps delivery inside the approved sites, whichever exchange a seller's deal reaches. Our version control guide covers numbering list versions.
When the master list changes
- The new list version number and the sites added or removed are written down before any seller is contacted.
- Each removed site is checked against each exchange's subset, so only the affected deals are changed.
- Each added site is checked for authorization on each exchange before it is sent to that exchange's seller.
- Each seller of record has confirmed in writing that its deal now matches the new version.
- The buyer side channel has been updated to the same version.
- The record for each exchange shows the list version its deal now carries.
Why does delivery differ between exchanges?
Delivery differs because each deal sells a different set of sites under different terms, even when all three were built from one list. Display & Video 360's troubleshooter (opens in a new tab) helps find the stage where volume drops. Its Total available requests metric is "The number of impressions matching the inventory sources selected in the Inventory dropdown," and losses are grouped as filtered impressions, eligible impressions, bids submitted and bid responses. Google notes that targeting data is not available for the Current day date range.
| Cause | What happens | Where to see it |
|---|---|---|
| Smaller site subset | The exchange sells fewer of the listed sites | Site subset in the exchange record; Total available requests |
| Reseller paths | Some sites reach the exchange through another seller, with fewer requests | Direct or reseller per site in the exchange record |
| Floors | One seller set a higher floor, so bids fall below it | Bids submitted stage, below deal floor losses |
| Formats | One deal offers fewer sizes or no video | Filtered impressions stage, creative mismatches |
| Priority at the publisher | Another deal or buyer wins the opportunity on that path | Bid responses stage, lost auctions |
| Targeting on the line item | Geography or frequency rules remove more requests on one exchange | Filtered and eligible impressions stages |
Uneven delivery is not a fault by itself. If spend follows the preferred exchanges marked in the master list, the setup is working. It becomes a problem when a deal with a large subset delivers little, which points to floors, formats or priority on that exchange rather than the list.
How should cross exchange deals be reported?
Report by site and exchange together, so the client sees one list and the trader sees each path. Display & Video 360's report dimensions (opens in a new tab) include Exchange, "The exchange where through which the ad is served," Inventory Source, the name of the deal, Inventory Source ID (External), the seller's own identifier for the deal, and App/URL, the name of a site or app. When deal information is unknown, the report shows Unknown or Unpermissioned Inventory Source.
| Column | Source | Question it answers |
|---|---|---|
| Site | App/URL dimension | Which approved site delivered? |
| Exchange | Exchange dimension | Which path carried it? |
| Deal ID | Inventory Source ID (External) | Which seller's deal, matching the seller's own report? |
| Preferred exchange | The master list | Did delivery follow the planned path? |
| On approved list | The master list version | Did any site outside the list deliver? |
Check the line items' inventory settings before reading the report. The inventory source targeting guide (opens in a new tab) says a line item without inventory source settings targets "open auction inventory on all enabled exchanges by default," and that "Deals are only targeted when you add the deal itself or deal group to targeting." Open auction rows in a deal report can mean a line item was left on that default.
What does a cross exchange setup look like on a real brief?
Fictional example
A northern building supply yard runs one list on three exchanges
An unnamed lumber and building supply yard with stores in Whitehorse and Yellowknife wants display and native ads beside local news, home building and renovation and northern living content across Yukon and the Northwest Territories, in English and French, priced in CAD. The planner's approved list holds 60 sites, several of them small regional publishers.
No single exchange sells all 60. The trading desk asks three sellers for deals, records each exchange's subset, and marks a preferred exchange for each site. Sites found on only one exchange stay in that deal alone. One insertion order holds the three deal line items with a shared frequency cap, and a channel built from list version 3 is applied to each.
Two weeks in, one exchange delivers far less than its subset suggests. The troubleshooter shows bids below the deal floor, so the desk raises the floor question with that seller instead of changing the list. When two sites close, version 4 goes to each seller, and the desk records each confirmation.
How does PlacementGraph show which exchanges sell each site on a list?
Frequently asked questions
Can the same deal ID be used on two exchanges?
No. The exchange or seller that creates a deal issues its ID, and the buying platform stores the ID together with that exchange. A second exchange creates its own deal with its own ID, even when the site list is identical. Record both IDs against the same master list version.
Should each exchange deal have the same floor?
Not necessarily. Each seller sets the floor on its own deal, and the sites, formats and paths behind each deal differ. Agree each floor separately, record it, and treat a big gap between floors as a question for the seller.
What if a site on the list is sold on only one exchange?
Keep it in that exchange's deal and mark that exchange as its preferred path. The site cannot be reached through the other deals, so it adds no duplicate requests. If that one path is a reseller, check that the site's ads.txt names the reseller's account.
Can a curator run one list across several exchanges for the buyer?
A curator can create deals on each exchange it works with, but each is still a separate deal with its own ID. Ask the curator for each exchange's site subset, deal ID and list version, so the buyer's records match the curator's setup.
Sources
- Managing exchanges (opens in a new tab)Google, Display & Video 360 Help
- Create an inventory source manually (opens in a new tab)Google, Display & Video 360 Help
- Inventory source targeting (opens in a new tab)Google, Display & Video 360 Help
- About synced deals (opens in a new tab)Google, Display & Video 360 Help
- About channels (opens in a new tab)Google, Display & Video 360 Help
- Troubleshoot your deals and line items (opens in a new tab)Google, Display & Video 360 Help
- Report dimensions (opens in a new tab)Google, Display & Video 360 Help
- Flattened bid requests (opens in a new tab)Google, Authorized Buyers Help
- OpenRTB 2.6 specification (opens in a new tab)IAB Tech Lab, OpenRTB repository
- Introduction to header bidding (opens in a new tab)Prebid.org
- ads.txt specification version 1.1 (opens in a new tab)IAB Tech Lab, Supply Chain Validation repository
- Manage frequency with frequency caps (opens in a new tab)Google, Display & Video 360 Help
Researched and written by PlacementGraph Research. Read how we research, source and update these pages. Corrections: diana@placementgraph.com.