Bidding Strategies

Target ROAS vs Target Impression Share: Return or Position

In short: Target ROAS is the value target inside Maximize Conversion Value: it predicts revenue per auction and bids up where payback looks good. Target Impression Share bids whatever your ceiling allows to hold a chosen page position at a chosen frequency, with no conversion input at all. One buys return, the other buys presence.

By the AdFlint research team · Fact-checked against current Google and Meta platform behavior · Last reviewed July 2026

Target Impression Share

Sets bids to reach a chosen share of impressions at a chosen page position, bounded by a maximum CPC ceiling you define.

You pick absolute top, top, or anywhere on the results page plus a percentage, and Google bids whatever is needed up to your ceiling. It is a visibility strategy, used mostly for brand defense and specific competitive terms where presence matters more than efficiency. The mistake is running it on non-brand terms with a high ceiling, since it buys position whether or not those impressions ever convert.

Full definition

Target ROAS

Bids automatically toward a chosen ratio of conversion value to ad spend, entered as a percentage in Google Ads.

It is the target field inside Maximize Conversion Value, and it only functions when your conversion values are accurate and varied. Google predicts value per auction and bids up where it expects payback. Raising the target reduces volume, and that trade is the mechanism rather than a defect. The common error is picking an aspirational number the account has never reached, which starves delivery outright.

Full definition

Side by side.

The differences that actually change what happens in your account.

	Target Impression Share	Target ROAS
What you enter	A page position and a percentage of impressions.	A percentage: conversion value divided by spend.
What limits spend	The maximum CPC ceiling you set, plus the budget.	The target ratio itself, plus the budget.
Uses conversion value	No. Value never enters the bid.	Yes. It is the entire basis of bidding.
Delivery behavior	Bids up to the ceiling whenever position demands it.	Declines auctions predicted to return below the ratio.
Typical home	Brand terms and a short list of must-win competitive terms.	Ecommerce and value-tracked lead gen carrying the revenue load.
Failure mode	Loose ceiling on non-brand terms, buying impressions that never pay back.	Aspirational target the account has never hit, which starves delivery.

What actually separates them.

Target Impression Share prices an auction by what the chosen position currently costs, while target ROAS prices it by predicted conversion value, so identical auctions get very different bids.

Target ROAS needs accurate and varied conversion values to function, and Target Impression Share needs no conversion tracking whatsoever.

The max CPC ceiling is the only cost control on Target Impression Share, and it is the setting most often left too high.

Raising a target ROAS reduces volume by design, while raising a Target Impression Share percentage increases spend by design, so the two dials move risk in opposite directions.

Target Impression Share will keep buying position on a term that has never returned a dollar, because nothing in the strategy can see that it has not.

Which one should you use?

Use Target Impression Share when

Competitors are bidding on your brand name and absence hands them a click you would have won cheaply.
A short list of high-stakes commercial terms where being missing loses the deal.
A launch window where share of voice is genuinely the deliverable.
You have set a firm max CPC ceiling and will review spend against it regularly.

Use Target ROAS when

Order values vary and real revenue is passed back with the purchase event.
You can compute a break-even return and want the bidder to respect a floor above it.
Margins differ enough by product that counting conversions misstates performance.
The campaign has enough conversion value history for the model to predict against.

Common questions.

Can I get both position and return out of one campaign?

Not from one bid strategy. A campaign honors one strategy, so you choose which constraint the bidder obeys. The usual structure splits them: a small brand or defense campaign on Target Impression Share with a hard CPC ceiling, and the non-brand campaigns on Maximize Conversion Value with a target ROAS.

My Target Impression Share campaign has terrible ROAS. Is it misconfigured?

Probably not. The strategy has no view of conversion value and never optimized toward it, so a poor return is the expected outcome rather than a fault. Judge it on impression share achieved and on what absence would have cost you. If return is the real yardstick, it is the wrong strategy.

Does Target Impression Share ignore my conversion tracking?

For bidding, yes. Conversions still record and report normally, so you can measure what the campaign produced, but no conversion or value signal enters the bid. That makes it safe to run before tracking is trustworthy and risky to run once you expect the bidder to protect efficiency.

Or stop choosing between them.

AdFlint picks the setting, writes the ads, and keeps optimizing inside the Google and Meta accounts you already own.

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