Microsoft Advertising Expands Average Target CPA and ROAS Metrics for Smart Bidding

On August 31, 2026, Microsoft Advertising announced an expansion of reporting for automated bidding strategies. Average Target Metrics became available in Campaign Overview, the main Campaigns grid, and the Portfolio Bid Strategies section.

Advertisers can now compare actual CPA and ROAS against average target values for a selected period, rather than only against current campaign settings.

What Are Average Target Metrics?

Average Target Metrics are metrics that reflect the historical average targets of automated bidding strategies.

Microsoft supports three metrics:

Avg. Target CPA — the average target cost per conversion over the selected period.
Avg. Target ROAS — the average target return on ad spend.
Avg. Target Impression Share — the average target impression share.

Unlike standard Target CPA and Target ROAS values, which show the current target setting, the new metrics account for changes made during the reporting period.

They are designed to analyze the performance of Maximize Conversions with Target CPA, Maximize Conversion Value with Target ROAS, and other applicable strategies.

How It Worked Before

Suppose an advertiser manages a Search campaign with a Target CPA of $20.

In the middle of the month, the advertiser decides to scale the campaign and increases the target CPA to $40.

At the end of the month, the actual cost per conversion is $30.

If the result is compared only with the current Target CPA of $40, it may appear that the campaign is significantly outperforming its target.

However, the algorithm operated with a Target CPA of $20 during the first two weeks, so evaluating the entire month against $40 would be inaccurate.

Previously, this type of analysis required specialists to reconstruct the history of setting changes and calculate average values manually.

This was particularly challenging for agencies that regularly adjust targets when scaling campaigns.

What Changed?

Microsoft Advertising now automatically calculates average target metrics for the selected period.

In the example above, if Target CPA was $20 for 15 days and $40 for the following 15 days, Avg. Target CPA would be $30.

Therefore, the actual CPA of $30 can be compared with the historical target of $30, rather than only with the current Target CPA of $40.

The same principle applies to Target ROAS and Target Impression Share.

For example, if an advertiser reduces Target ROAS from 500% to 300% to increase conversion volume, the new metric makes it possible to evaluate results against the targets that were in effect during the period.

It is important to consider the calculation methodology. At the campaign and portfolio strategy levels, Microsoft uses historical daily target values.

At the account level, it also calculates a weighted average of campaign targets based on their daily spend, then averages the daily results.

As a result, the account-level value may differ from a simple arithmetic average of individual campaign targets.

Where to Find the New Metrics

Microsoft first introduced Average Target Metrics in the Bid Strategy Report in May 2026.

The August update expanded their availability to the main reporting interfaces:

Campaign Overview — campaign performance overview.
Campaigns Grid — the campaign table.
Portfolio Bid Strategies — portfolio strategy reporting.

In the Bid Strategy Report, the metrics are available at the campaign, account, and portfolio levels.

Developers can also access them through the Microsoft Advertising Reporting API. The field names are AvgTargetCPA, AvgTargetRoas, and AvgTargetImpressionShare.

How to Use Average Target Metrics

The primary use case is evaluating Smart Bidding performance after target changes.

For example, an agency increases Target CPA to scale lead generation. One month later, it compares actual CPA, Avg. Target CPA, conversion volume, and spending.

This helps determine how closely the results align with the targets that were in effect, rather than only with the most recently configured target.

For e-commerce, a similar analysis can be performed using Avg. Target ROAS.

The new metrics are also useful for comparing multiple campaigns and preparing client reports, especially when advertisers frequently change their automated bidding strategy settings.

However, an average target does not replace a comprehensive analysis. Advertisers must consider conversion volume, budget changes, attribution delays, and demand trends.

In addition, actual CPA for a given period may differ from Avg. Target CPA: target values guide the algorithm but do not guarantee an exact result.

Do the New Metrics Affect Advertising Performance?

Average Target Metrics are purely analytical tools.

They do not change bidding algorithms, accelerate Smart Bidding learning, or independently increase ROAS.

Microsoft also does not provide independent data showing improved campaign performance as a result of introducing these metrics.

The main advantage of the update is more accurate measurement of automated bidding strategy performance, particularly in accounts where Target CPA and Target ROAS are adjusted regularly.

Sources

Microsoft Advertising: AI Max for Search and Other Product News for August 2026. Microsoft Advertising Blog
Microsoft Advertising: New Import Center and Other Product News for May 2026. Microsoft Advertising Blog
Microsoft Learn: BidStrategyReportColumn. Microsoft Learn