How to Use Seasonal Adjustments in Google App Campaigns

Your app promotion is about to start, but the expected lift is not evenly distributed. One ad group’s offer is central to the event; another ad group may behave much as it normally does. Applying one optimistic forecast to both gives automated bidding the wrong level of confidence.

Google Ads’ new control is meant for that problem. If the beta appears in your account, you can give Smart Bidding a temporary conversion-rate forecast for selected App campaign ad groups instead of applying the same adjustment more broadly. The important part is not finding the setting. It is choosing the right scope and entering a forecast you can defend.

Treat the adjustment as a forecast, not a performance target

Google Ads is testing ad-group-level seasonal adjustments for App campaigns as a beta. This adds a third scope alongside campaign-type and specific-campaign adjustments.

A seasonal adjustment tells automated bidding how much you expect the conversion rate to change during a defined promotional period. It does not create that change, guarantee more conversions, or serve as a general instruction to bid more aggressively.

That distinction should shape your planning. Start with an operational forecast: which conversion rate will temporarily change, for which part of the account, during which dates, and by how much? Only then should you translate the forecast into a Google Ads adjustment.

If the business case is merely that a promotion should be successful, you do not yet have enough information. A seasonal adjustment needs an expected conversion-rate change. Hope, a larger budget, heavier traffic, or a higher conversion-volume goal is not the same thing.

Choose the narrowest scope your forecast can support

The new option does not mean ad-group scope is automatically best. More granularity is useful only when different parts of the account are genuinely expected to respond differently.

Use a simple test before choosing the beta scope: can you explain why the selected ad group’s conversion rate should change differently from the excluded groups? Offer eligibility, promotional relevance, and a real difference in the event’s reach can support that decision. A vague belief that one group is more important cannot.

Suppose one App campaign contains ad groups tied to different propositions, but the promotion applies to only one of them. A campaign-level adjustment would tell Smart Bidding to expect the same temporary effect from unaffected traffic. The ad-group beta lets you confine the forecast to the part of the campaign that actually has a promotional reason to change.

The reverse is also true. If every ad group is exposed to the same offer and you expect a comparable conversion-rate movement throughout the campaign, splitting the adjustment adds configuration without improving the forecast. Match the control boundary to the business event, not to the most detailed setting available.

Calculate the input from conversion rate, not conversion volume

The adjustment is an estimated relative change in conversion rate. Build it from two values measured on a comparable basis:

• B: the baseline conversion rate you would expect without the temporary event.
• P: the conversion rate you expect during the promotional window.

Calculate the adjustment as: ((P / B) – 1) x 100.

If you expect the conversion rate to rise by 50% during a three-day sale, the feature’s documented example uses a +50% adjustment for that three-day period. That is a relative conversion-rate forecast. It is not a prediction that total conversions will necessarily increase by 50%, and it is not a promise that the forecast will materialize.

This is where many weak adjustments begin: conversion volume rises in a planning spreadsheet, and the same percentage is copied into the seasonality control. Volume and rate are not interchangeable. More traffic can produce more conversions while the conversion rate remains unchanged. In that case, the volume forecast alone does not justify a conversion-rate adjustment.

Use this sequence to produce a cleaner estimate:

1. Define the exact promotional start and end so the estimate covers only the temporary event.
2. Choose a baseline that uses the same conversion definition and a comparable measurement setup.
3. Estimate the promotional conversion rate independently from your traffic or spend forecast.
4. Calculate the relative change between the promotional rate and the baseline rate.
5. Repeat the calculation by ad group only where you have a reason to expect different responses.
6. Record the baseline, expected rate, calculation, scope, and promotional assumption so the number can be reviewed later.

Do not manufacture different percentages merely because the interface permits separate ad-group inputs. If the evidence supports one shared estimate, use the corresponding broader scope. If it supports no credible conversion-rate estimate, skipping the seasonal adjustment is more defensible than feeding Smart Bidding an arbitrary signal.

Run a preflight check, then review the forecast after the event

Before the promotion

Because the ad-group option is a beta, first confirm that it is actually available in the account you plan to change. If it is absent, do not force the forecast into a broader scope unless that broader scope is itself accurate.

• Match the adjustment’s dates to the period when the temporary conversion-rate change is expected.
• Verify the selected campaign or ad groups against the actual promotion setup.
• Confirm that the conversion action and measurement setup used for the forecast are operating as expected.
• Check that the percentage represents a conversion-rate change, not an increase in traffic, spend, installs, or raw conversion count.
• Write down why included ad groups should change and why excluded ad groups should not.
• Assign someone to verify that the promotion and its measurement are live when the period begins.

Take extra care with an optimistic estimate. The adjustment becomes an input to automated bidding, so an exaggerated forecast can steer bids using a conversion rate that never appears. The safest input is not the most ambitious percentage; it is the percentage best supported by your promotion plan and comparable performance data.

During the promotional window

Monitor the assumptions behind the adjustment, not just the headline conversion count. Confirm that the offer is active, eligible users can reach it, conversion tracking is functioning, and the selected ad groups are the ones receiving the promotional effect. A traffic surge can make total conversions look healthy even when the expected conversion-rate lift has not occurred.

Also keep the adjustment’s role in perspective. It helps Smart Bidding respond to an expected temporary change; it does not certify the accuracy of that expectation. If the event setup differs from the plan, treat that as a forecast problem rather than proof that the bidding system must somehow deliver the original percentage.

After the promotion

Compare the actual conversion-rate movement with the estimate at the same scope and across the same promotional dates. If you configured selected ad groups, evaluate those groups rather than using a campaign-wide average that can dilute or exaggerate their result.

Preserve the forecast error and its likely cause. Note whether the offer, audience exposure, measurement, or scope differed from the assumption. This gives you a better starting point for the next temporary event and helps prevent an unsupported percentage from becoming an inherited account convention.

Key takeaways

• A seasonal adjustment is a temporary conversion-rate forecast for Smart Bidding, not a guaranteed result or a general volume target.
• The beta ad-group scope applies to selected ad groups within App campaigns and is useful when their expected promotional responses genuinely differ.
• Campaign-type or specific-campaign scope remains appropriate when the same forecast reasonably covers the broader selection.
• Calculate the input from expected conversion-rate change, not from projected clicks, installs, spend, or total conversions.
• Keep the adjustment aligned with the promotional window, validate measurement, and compare the actual rate change with the original estimate afterward.

Before your next promotion, write the forecast in one sentence: conversion rate for this scope should change by this percentage during these dates because of this temporary event. If every part of that sentence is defensible, configure the matching scope. If the sentence breaks down at the percentage or the scope, improve the forecast before you touch bidding.

References

• Search Engine Land – Google Ads tests ad group-level seasonal adjustments for App campaigns