Promotion Mode, explained

How it works

You pick a start date and an end date between 3 and 14 days apart, a Target ROAS tolerance between 5% and 90%, and, if you want it, an extra daily budget on top of your normal one. The page's example: a campaign at a 500% Target ROAS and a $100 daily budget, set to a 20% tolerance and a $50 budget increase, runs at "a 400% Target ROAS" and $150 a day for the sale, then goes back to 500% and $100.

It's built on Smart Bidding Exploration. Campaigns in an active promotion "will always utilize exploration, even if the standalone setting is not enabled." If you already run Exploration, the two tolerances add up: 20% plus 20% is "40%." On eligibility, the page says: "Promotion Mode will initially be powered by Smart Bidding Exploration for Search inventory only. Retail will be available in November 2026."

To set it up, open a campaign's settings, expand the Promotion mode panel under "Budget and bidding optimization," and check "Ramp up spend quicker on promotion dates." While it runs, the campaign list shows "(Promotion mode on)" in the Budget column.

The rules to know

• Changes go through Promotion Mode: during an active promotion, "You cannot change your baseline Target ROAS or baseline average daily budget outside of Promotion Mode."
• Dates: you can't change the start date once it begins, but you can move the end date as long as the flight stays within 14 days. You can also turn the setting off, which ends the promotion and returns the campaign to its baseline.
• Budget types: it works with average daily budgets and campaign total budgets, but "the extra daily budget option is not available for campaign total budgets."
• Spending limits still apply: "you will not be billed more than twice your daily budget in a single day."
• No CPC bid limits: the page says not to use them, because they restrict "the system's ability to bid opportunistically on high-performing new traffic."
• Performance Max: Exploration "only applies to search inventory or search ads," so campaigns that serve heavily on other networks "will not see as large of an effect."

Promotion Mode vs. seasonality adjustments

The page draws the line itself. With Promotion Mode, bidding "will aim to achieve the lowered ROAS target." With seasonality adjustments, "smart bidding will continue aiming to achieve the original target." Promotion Mode is set per campaign; seasonality adjustments work at the campaign or campaign type level.

What I'd do this week

Google's page stops at the rules; the rest is my suggestion.

Check eligibility before you plan around it. If the campaigns you'd use for a holiday sale sit in a portfolio strategy or a shared budget, they can't use Promotion Mode as things stand.

Build early. The page says new campaigns should be set up "at least 48 hours prior" and existing ones should have run "for at least one full conversion cycle using a daily budget." For a sale that starts near the end of November, that means deciding this month.

Start with a modest tolerance. A big drop in the target plus Exploration on top can add up fast, and the page's own advice for running both is to monitor "closely."

Leave room afterward. The page says to allow "1 to 2 conversion cycles" for Smart Bidding to settle back after a large change, so I wouldn't judge the week after the sale against a normal week.