Dynamic allocation

Ad Manager guaranteed line items compete with remnant line items when Ad Exchange line items are eligible. Although this article specifically covers Ad Exchange line items, AdSense monetization behaves in the same manner.

Customized numeric priority values

Some networks can change numeric priority value of line item types. Changing the priority value can adversely affect ad selection and is not recommended.

Learn more about the Ad Manager ad selection process and how Ad Manager counts impressions and clicks.

House line items and the auction

House line items only serve when no remnant line items (Network, Bulk, Price Priority), Ad Exchange or Exchange Bidding demand are available to serve. That is, House line items are treated as if they have a $0 rate and do not compete on price via dynamic allocation.

House line item CPM determines ranking of eligible House ads but do not need to meet any floor price set in unified pricing rules in order to be eligible to serve an ad, thereby effectively serving as a fall-back ad. Learn more

About dynamic allocation

Dynamic allocation is a network-level mechanism designed to maximize your remnant and Ad Exchange revenue without compromising reservations. With dynamic allocation, both remnant and Ad Exchange line items are given a chance to serve if Ad Exchange/AdSense is eligible for the request (using line item targeting for Ad Exchange/AdSense or ad unit monetization for AdSense). Configure settings in Ad Manager and Ad Exchange to control which inventory is eligible to compete, and how.

Watch related Publisher University training (Dynamic allocation)

Products that work with dynamic allocation

The following Google products can serve ads to Ad Manager networks using dynamic allocation:

  • 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.
  • AdSense: Provides fewer controls and more straightforward management. 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.

Line items types mentioned in this article

  • Line items with delivery goals: Line items that have delivery goals, either an absolute impression/click goal or a percentage of delivery. These include Sponsorship, Standard, Network, Bulk, or House line item types.
  • Line items without delivery goals: Line items that compete on the basis of CPM but do not have delivery goals—that is, they have unlimited delivery goals. These include Price Priority, Ad Exchange, and AdSense line item types. 
  • Guaranteed line items: Sponsorship and Standard line items, which fall in the priority range of 1 to 11
  • Remnant line items: Price Priority, Network and Bulk line items, with a priority 12
  • Ad Exchange line items: Also with a priority of 12
  • House line items: House line items have a priority of 16

Overview of how dynamic allocation works

Dynamic allocation is a yield-maximizing capability of Google Ad Manager that allows Ad Exchange to compete in real time with line items booked in Ad Manager as either remnant or guaranteed. This competition is on an impression-by-impression basis. You can configure settings in Ad Manager and Ad Exchange to control which inventory is eligible to compete by using line items in Ad Manager and rules in Ad Exchange. Since dynamic allocation is active across your entire network, you don’t need to change any network-wide configurations.

If you only have remnant line items competing with an eligible Ad Exchange line item, Ad Exchange competes in real time with the highest CPM of the remnant line items that haven't reached their goal (absolute or by percentage).

If you have multiple AdSense or Ad Exchange line items with overlapping targeting, then only one is eligible to compete. If identical priority levels are set for the Ad Exchange and AdSense line items, then Google Ad Manager randomly picks one to compete without regard for historic CPM values, which may not be an optimized delivery yield.

If you have guaranteed line items of a higher priority (numerically lower or equal) than the eligible Ad Exchange line item or Price Priority line items, dynamic allocation can evaluate and set the reserve price as a temporary CPM or "opportunity cost" in Ad Exchange without causing under delivery of the guaranteed line item. This allows Ad Exchange or remnant line items to serve when they pay more than the opportunity cost of not serving the guaranteed line item.

Watch related Publisher University training (Ad selection)

Determining whether Ad Manager or Ad Exchange serves an ad

If the ad server determines that an Ad Exchange line item is eligible to compete for an impression, Ad Manager goes through the following steps to determine whether the Ad Exchange or the Ad Manager-booked line item should serve an ad.

Steps of dynamic allocation

Step 1 There's an ad request to Ad Manager 
Step 2 Ad Manager finds the best guaranteed line item eligible to serve for the ad request and calculates a temporary CPM based on the line item's current delivery
Step 3 Ad Manager finds an eligible remnant line item with the highest CPM
Step 4 Ad Manager calls Ad Exchange to find ads which can beat the temporary CPM of guaranteed line item or the CPM of the remnant line item
Step 5 Ad Manager selects the line item with the highest CPM to serve an ad, protecting guaranteed ads in all cases

Dynamic allocation illustration

Finding the best guaranteed line item

Ad Manager finds the best guaranteed line item eligible to serve for the ad request and calculates a temporary CPM based on the line item's current delivery.

Selection of the best guaranteed line item is based on many factors, including line item priority and how close each line item is to being on schedule. Learn more in the Ad selection white paper.

For the following example, we'll designate the best guaranteed line item as Line Item A.

Ad Manager creates a temporary CPM for Line Item A. This value can be thought of as an opportunity cost based the line item's progress and Ad Exchange historical bid data, to optimize publisher revenue. In general, the lower a line item’s Satisfaction Index (SI) (that is, the more behind schedule it is), the higher the temporary CPM that’s passed to Ad Exchange. Dynamic allocation uses this temporary CPM value to allow Line Item A to compete against eligible Ad Exchange and remnant line items in Step 2, competing with other sources.

Competing with other sources of demand to maximize yield

Lower-priority remnant line items and Ad Exchange line items do not compete when either of the following are eligible to serve: a Sponsorship line item with a goal of 100% or a combination of Sponsorship line items at the same priority with goals that add up to greater than or equal to 100%. Similarly, Ad Manager may prevent lower-priority remnant and Ad Exchange line items from competing if Line Item A is a guaranteed line item that is at risk of not delivering in full (for instance, if Line Item A is far behind schedule).

Otherwise, Ad Manager looks at remnant/non-guaranteed and Ad Exchange line items eligible to serve to the same impression:

  • If there is no remnant or Ad Exchange line item eligible, Ad Manager serves Line Item A and serving is complete.
  • If there are several contending remnant and Ad Exchange line items, Ad Manager ranks all eligible remnant line items by their value CPM. It chooses the highest value remnant line item, which we refer to as Line Item B for brevity. If there is no value CPM, Ad Manager uses the line item CPM instead.
  • Among eligible Ad Exchange line items, the highest priority (lowest priority number) line item is selected. If two or more Ad Exchange line items have the same highest priority, then one is chosen by Ad Manager.

Ad Manager then calls Ad Exchange (using the selected Ad Exchange line item) to see if it can provide a bid with a higher price than both the temporary CPM of Line Item A and the value CPM of Line Item B. Calling Ad Exchange only means that Ad Exchange gets a chance to compete with Ad Manager; it doesn't necessarily mean that an Ad Exchange ad gets served (see Step 3 for that).

Determining if Ad Exchange serves an ad

If Ad Manager calls Ad Exchange in Step 2, eligible Ad Exchange ads compete with Line Item A and Line Item B on a CPM basis. The reserve price for Ad Exchange ads is at least the maximum of the temporary CPM from guaranteed Line Item A and the remnant value CPM from Line Item B. (The reserve price may be higher than this maximum due to other publisher configurations, such as rules.)

  • If an Ad Exchange ad can beat the reserve price (at least the maximum of the remnant value CPM from Line Item B and the temporary CPM from guaranteed Line Item A), then that Ad Exchange ad serves.
    Any Ad Exchange ad selected to serve still adheres to the conditions of Preferred Deals or Private Auctions, if applicable.
  • If no eligible Ad Exchange ad can beat the reserve price, Ad Manager fills the impression with the line item that provided the highest CPM in Step 2: Either Line Item A based on its temporary CPM, or the remnant Line Item B that provided the maximum CPM.

When we refer to the CPM of an Ad Exchange ad, that CPM is on a net basis to the publisher (that is, it takes into account Ad Exchange's revenue share).

Example

Your network is enabled for dynamic allocation and you use Ad Exchange with the default settings. When a visitor stops by your site, an Ad Exchange line item is eligible to serve to the impression, as are a number of guaranteed line items. The best guaranteed line item is at priority 10. With dynamic allocation, Ad Manager looks at all the eligible guaranteed line items and calculates a temporary CPM for the winner. The winning guaranteed line item is late on delivery. The temporary CPM is calculated as $6.50.

There are 2 other remnant line items with CPMs of $3 and $5, respectively. Ad Manager sends the maximum of the temporary CPM ($6.50) and the highest eligible remnant CPM ($5) to Ad Exchange. As it turns out, there’s no eligible Ad Exchange ad that can beat $6.50, and so the guaranteed line item fills the impression.

General notes about dynamic allocation

  • Note that the dynamic allocation process protects delivery of guaranteed line items by dynamically adjusting the temporary CPM. Therefore, a guaranteed line item that is behind schedule wins often enough to stay on pace to satisfy its goal and pacing settings. If the temporary CPM is too high, Ad Manager doesn't make the call to Ad Exchange, which explains why sometimes the number of "Impressions competing" is lower than the "Eligible impressions" in the Ad Exchange opportunities report.
  • Since Ad Exchange ads compete with remnant line items on a CPM basis, the dynamic allocation process maximizes publisher yield regardless of demand source.
  • By dynamically allowing competition between Ad Manager guaranteed line items and remnant line items/Ad Exchange ads (when the latter have a sufficiently high bid), Ad Manager maximizes efficiency and increases publisher yield/advertiser value compared to a static allocation/“waterfall” system.

Addendum: With configurable priority

If your network is eligible for configurable priority and it is activated, Ad Exchange or Price Priority line items can be set to any priority. If the priority of the Ad Exchange/Price Priority line item is higher than that of the selected Standard or Sponsorship line item, Ad Manager doesn’t calculate a temporary CPM for the reservation line item. In other words, line items with a lower priority than that of the Ad Exchange/Price Priority line item are considered remnant inventory and compete based on price.

Price Priority line items with a custom priority can change the priority level where other line items are considered remnant or guaranteed, but this only applies when an Ad Exchange/AdSense line item is also eligible.

Using configurable priority and placing Ad Exchange/Price Priority line items at a higher priority than Standard or Sponsorship line items prevents dynamic allocation from taking line item pacing into consideration, which may cause delivery issues for your Standard or Sponsorship line items. For this reason, we don't recommend using configurable priorities in conjunction with dynamic allocation, as it increases complexity in your account.

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