What is Target impression share?

Target impression share bids to win a chosen share of the auctions a campaign is eligible for. The advertiser sets the share, chooses where the ad should appear — anywhere on the page, top of page, or absolute top — and sets a maximum cost-per-click ceiling. The platform then bids whatever it takes, up to that ceiling, to hit the share.

What separates it from every other automated strategy is what it optimises. The conversion-based strategies estimate the value of an impression and bid accordingly. This one does not estimate value at all. It has been told to appear, and it appears.

That makes it the right tool for a small number of jobs and an expensive habit everywhere else.

Two mechanisms compound.

The first is that value is not in the calculation. An auction where the click is nearly worthless and one where it is valuable are treated the same, because the strategy is counting appearances rather than outcomes. A conversion-based strategy declines the first; this one buys it.

The second is that impression share gets steeply more expensive at the top. Winning half the eligible auctions means beating the weakest half of the competition. Winning ninety percent means beating nearly everyone, including the advertisers who value that traffic most and bid accordingly. The cost of the last few percentage points is disproportionate to the volume they add.

Together these mean that a high target on a broad keyword set produces exactly the outcome the arithmetic predicts: full coverage, a great deal of spend, and a cost per conversion nobody would have agreed to in advance.

Brand defence. A business wants its own name covered, and wants a competitor bidding on that name kept below it. The traffic is cheap, the conversion rate is high, and the cost of losing the position is a customer handed to somebody else. This is the case the strategy fits best, and a near-total target on exact-match brand terms is defensible in a way it is nowhere else.

A launch or an event window. Presence for a defined period, where being seen is the objective and the window has an end date somebody wrote down.

Market entry. A business establishing itself in a category where nobody searches for it by name yet, willing to pay for visibility as an investment, with a review date attached.

What all three share is that the value is strategic and the advertiser has decided it is worth paying for. The strategy is a way of executing that decision, not a way of discovering whether it was right.

As a general performance strategy. It optimises the wrong thing. An account using it broadly has swapped an outcome objective for a visibility one and will find out the cost in the accounts rather than in the platform.

On a broad or poorly qualified keyword set. The strategy will dutifully buy a high share of traffic the business did not want. Narrowing the keywords before raising the target is the single most effective way to make it affordable.

Without a ceiling. The maximum cost-per-click setting is not optional in practice. Without it, the strategy will bid whatever the target requires, and a well-funded competitor raising their bids drags the price up with no brake at all.

As a response to a lost-to-rank column. Rank losses are frequently correct — the account declining auctions it cannot afford. Switching to a visibility strategy converts a disciplined decline into an expensive purchase.

The three options are different products at different prices.

Anywhere on the page is the cheapest and the weakest. Appearing below several competitors captures a small share of the clicks.

Top of page is the useful middle for most defensive work: above the organic results, in the block people actually look at.

Absolute top is the first position and costs materially more than the position below it. It is worth buying where being first is the point — a brand term a competitor is contesting — and rarely worth it otherwise.

A common and avoidable error is to pick absolute top by default because it sounds like the best option, then to conclude the strategy is unaffordable. Top of page frequently delivers most of the benefit at a fraction of the premium.

A visibility strategy will never tell you it has stopped being worth the money, because it is not measuring that. There is no number inside it that falls when the spend stops earning its place, so the discipline has to come from outside.

Five things belong in that review, and they are the whole of the maintenance this strategy needs.

Check the target against the job. Brand defence wants near-total coverage on exact terms; almost nothing else does, and a round number chosen because it sounded decisive is the most common way this strategy becomes expensive.

Confirm the maximum cost-per-click ceiling is still set and still sensible. Without one the strategy will pay whatever the target requires, and the target has no idea what a click is worth.

Narrow the keyword set before raising the target. Buying a high share of poorly qualified traffic is the most expensive use of this strategy there is, and the remedy is subtraction rather than a smaller share.

Confirm the position setting is the one you meant. Absolute top costs materially more than top of page, and the two answer different questions.

Read cost per conversion against the ceiling that contribution and close rate imply.

So the review has to be scheduled rather than triggered. Read cost per conversion for the campaign against the ceiling that contribution and close rate imply, on a regular cadence, and be prepared to lower the target or narrow the keywords when the answer moves.

And keep the strategic case written down. A target impression share campaign set up for a launch that ended a year ago is one of the more common quiet expenses in a mature account, still faithfully buying a position nobody has needed since.

Two numbers matter once the strategy is running, and they answer different questions.

Achieved share against target says whether the strategy is managing to do what it was told. A campaign persistently under its target with the ceiling binding is telling you the ceiling is lower than the market requires — which is useful information and frequently the right place to stop rather than the problem to fix.

Lost to rank against lost to budget still applies. A visibility strategy hitting its ceiling loses to rank; one out of money loses to budget. The remedies differ as they always do, and the second one is worth checking before concluding the auction is expensive.

A campaign comfortably hitting a high target well under its ceiling is the pleasant case, and it usually means the keyword set is narrow and the competition thin — which is what brand defence looks like when it is working.

Before reaching for a visibility strategy, it is worth asking whether the objective can be expressed as an outcome instead.

Frequently it can. "We need to be on the first page for these terms" is often a proxy for "we need the conversions those terms produce", and a conversion-based strategy with an appropriate target will buy the position wherever the position is worth buying — and decline it where it is not, which is the part the visibility strategy cannot do.

The cases where the proxy is not a proxy are the ones listed above: brand defence, a launch, a market entry. There the appearance genuinely is the product, and no conversion target expresses it.

Distinguishing the two before choosing the strategy avoids the most common way this tool ends up in an account, which is as an answer to impatience with an outcome-based campaign that was declining auctions for good reasons.