Inventory forecasting


Inventory forecasting is available only to Microsoft Advertising Ad Server customers.

For a publisher to commit to delivering against an advertiser's budget, that publisher needs a way to forecast how much inventory is available for the advertiser to buy. In addition, the publisher needs a way to discover inventory contention. Inventory contention occurs when there are multiple line items competing for the same inventory. Understanding contention is important so the publisher can make prioritization decisions when conflicts occur.

This page describes:

  • What forecasting features are available
  • How inventory forecasting works at a high level
  • The types of forecasting that are available

Microsoft Monetize forecasting tools

You can forecast on standard, guaranteed delivery, and programmatic guaranteed selling line items. When you create or edit a line item of either type, there will be a Check Availability button at the bottom of the Create or Edit screen:

Screenshot that shows the Check Availability button.

Click Check Availability to open the Forecasting pane. This pane shows you a chart with delivery goals and capacity for the current line item. Click on Contending Line Items to expand that section and see other line items that are contending for the same inventory. You can filter the contending line items based on priority.

Screenshot that shows the components of the Forecasting pane.

For line items with a vCPM revenue type, the availability and contention forecast numbers are based on viewable impressions. For more information, see Introduction to Viewability.

Types of inventory forecasting

Inventory forecasting provides the following information:

  • Capacity: The total amount of inventory available.

  • Availability: The amount of available inventory that isn't already booked and matches the proposed targeting and flight dates for the line item.


    Although Availability is returned for standard line item forecasts, it's calculated from the perspective of a guaranteed line item. Therefore, Availability shouldn't be relied on as a definitive availability estimate for standard line item types.

  • Contention: The number of line items that will be competing for this same inventory given the proposed targeting and flight dates.

  • Delivery: Whether the line item will deliver in full. For guaranteed delivery line items, see the Unlikely to Deliver filter in Explore Global Line Items.

Inventory forecasting features

Important features of our forecasting capability include:

  • Automatic adjustment to seasonal traffic patterns.

  • Spike detection and mitigation.

  • Forecasts based on the actual line item and campaign targeting, including segment and geographic targeting, and frequency capping.

  • Forecasts based on log-level, per-impression data rather than on sampling.

  • Forecasts that can be made up to 15 months in the future.

  • Daily capability and availability data for the full flight of a line item.


    Forecasting is daily; individual start and end times are not considered.

  • Forecasts that account for multiple impressions required for roadblocking.

How inventory forecasting works

Our forecasting solution works by consuming log-level (per-impression) data directly from the ad server and feeding it into our analysis engine. The analysis engine then uses that data to generate forecasts by actually simulating how the ad server will behave in future auctions. It's able to run this simulation to a high degree of accuracy because it has access to:

  • Large amounts of impression-level historical data about previously sold inventory, including how it was targeted.
  • Low-level knowledge of the ad server's behavior for Guaranteed Delivery Auction Mechanics, targeting, and pacing.

Forecasting for roadblocks

Forecasting for a line item that includes roadblocks is calculated a little differently than line items serving a single creative at a time. With roadblocks, multiple creatives must serve at once for the line item to deliver, so forecasting takes that into account. For roadblocks, capacity and availability numbers are calculated per creative, then summarized using the lowest availability and capacity numbers. These number are multiplied by the number of creatives in the roadblock to create a final forecast summary.

See Target Your Inventory with Roadblocking for general roadblocking information.