How does viewable CPM bidding work with placement lists?
Part of Google Ads placements
The short answer
Viewable CPM (vCPM) is a manual Google Ads bid strategy for Display Network only campaigns: you bid per 1,000 viewable impressions and pay for impressions measured as viewable, where a display ad counts once half of it is on screen for one second. Bids can be set per ad group or per placement, which suits a hand picked site list.
Key takeaways
- Active View counts a display ad as viewable at 50 percent of its area on screen for one second, 30 percent for ads of 242,500 pixels or more, and video at 50 percent for two seconds of play.
- vCPM is offered for Display Network only campaigns; Google's Display to Demand Gen migration page lists viewable impressions bidding as not supported in Demand Gen.
- Viewable is not the same as seen or suitable: Active View cannot guarantee a person looked at the screen, so site review still happens before the bid.
What is viewable CPM bidding in Google Ads?
With viewable CPM, you bid on 1,000 viewable impressions and you pay for impressions that are measured as viewable.
Viewable CPM, written vCPM in the account, is a manual bid strategy: the buyer names the highest price for a thousand viewable impressions. Google's vCPM help page (opens in a new tab) says it is selected when you choose CPM bidding for a "Display Network only" campaign, that it is not available for Search Network only campaigns, and that Max. CPM is no longer available as a bid strategy.
Definition
- Viewable CPM (vCPM)
- A manual Google Ads bid strategy in which the advertiser bids for 1,000 viewable impressions on the Display Network and pays for impressions Active View measures as viewable.
Google lists the benefits on the same page: you pay only for impressions measured as viewable, and bids are optimized to favor ad slots more likely to become viewable. It also carries two warnings. If a campaign uses vCPM and its ads are not compatible with the strategy, those ads won't run. And a small portion of served impressions might be charged.
What does Google count as a viewable impression?
Google measures viewability with Active View, which its Active View page (opens in a new tab) describes as a technology on YouTube and certain Display Network websites and apps. Google says Active View metrics follow the Media Rating Council's guidelines for measuring viewability. The thresholds depend on the ad's format and size.
| Ad | Share of the ad on screen | Time required |
|---|---|---|
| Display ad | At least 50 percent of its area | At least 1 second |
| Large display ad, 242,500 pixels or more | At least 30 percent of its area | At least 1 second |
| Video ad | At least 50 percent of its area | At least 2 seconds while the video plays |
The vCPM page phrases the video rule as an ad that plays continuously for 2 seconds or longer, the same bar. A large ad is one whose width times height reaches 242,500 pixels, so a 970 by 250 billboard qualifies and a 300 by 250 rectangle does not.
Some impressions cannot be measured. Google's viewability metrics page (opens in a new tab) separates measurable impressions from non-measurable ones, which appeared on sites, apps or devices Active View could not read; a non-measurable impression "doesn't mean that your ad was or wasn't noticed." Viewable rate divides viewable impressions by measurable ones, while viewable impression distribution divides by all impressions.
Which campaign types use viewable CPM?
| Campaign type | What Google's pages say about vCPM | Source |
|---|---|---|
| Display, Display Network only | Available: chosen when CPM bidding is selected for a Display Network only campaign | 3499086 (opens in a new tab) |
| Search Network only | Not available | 3499086 (opens in a new tab) |
| Demand Gen, including migrated Display campaigns | Viewable impressions bidding listed as not supported in Demand Gen, with Max Clicks named as the alternative | 17051545 (opens in a new tab) |
| Video | Two readings on one page: the bid strategy table marks vCPM as available in video, charged per 1,000 viewable impressions, while the subtype table lists Target CPM, Target CPV and conversion strategies, with no vCPM | YouTube Help 2375425 (opens in a new tab) |
How does vCPM bidding interact with placements?
Placement targeting and vCPM can be combined. Google's bidding basics page (opens in a new tab) says viewable CPM bidding, like CPC manual bidding, lets you set bids at the ad group level, or for individual placements. The placement targeting page (opens in a new tab) adds that you can raise the bid on one site that works well and lower it on another, and that popular sites or videos may need higher bids to get impressions.
Google's bid strategy guide (opens in a new tab) names placement targeting as one of the cases for manual vCPM: when you target particular placements, not just keywords, bidding for impressions can help ads reach an audience likely to be interested. The vCPM page says the bid reflects the value of an ad appearing in a viewable position on a given placement.
Three steps to set vCPM bids on a placement ad group
- Set the ad group default. The default vCPM bid covers placements without a bid of their own; Google labels it "(viewable)" in the statistics table.
- Raise bids only where there is a reason. A site central to the brief, or a popular site that may need a higher bid to win impressions, gets its own placement bid, recorded with the reason.
- Keep the ad group pure. Placements, topics and keywords in one ad group combine as any match, per Google's content targeting page (opens in a new tab), so a topic added beside the list lets the vCPM bid buy pages outside it.
A placement bid sets a price; it does not reserve the site, since buyers compete with other advertisers on placements they select. A low vCPM bid on a short list can leave budget unspent, and a high bid on one site can concentrate delivery there.
When should a placement plan use vCPM?
Google's bid strategy guide recommends manual vCPM when ads are designed to raise awareness rather than drive clicks, when particular placements are targeted, and when the message sits in the ad itself. It says vCPM probably isn't for a campaign seeking a direct response such as a purchase or a form.
| Strategy | Fits a placement plan when | Limits to weigh |
|---|---|---|
| vCPM, manual | The goal is awareness, the list is hand picked, and the buyer wants to set bids per site | Manual upkeep; not supported in Demand Gen per the migration page; a small portion of served impressions might be charged |
| Manual CPC | The goal is site visits and the buyer wants per placement control of click bids | Manual upkeep; listed as not supported in Demand Gen, with Target CPC as the alternative |
| Maximize Clicks | A steady budget and traffic goal with no wish to manage bids by hand | Individual CPC bids can't be set, only a campaign maximum, per Google's guide |
| Smart Bidding (Target CPA, Target ROAS) | Conversion tracking is in place and conversions are the goal | Bids are set by the system, so per placement price control is gone |
The bid strategy measures position on screen; the list decides where. A site list built for context and suitability, bought on vCPM, pays for ads that could be seen on pages the planner approved. The ANA's 2023 definition of made for advertising sites (opens in a new tab) says such sites exhibit good viewability rates, so the viewability and site quality guide treats the two as separate checks.
What does a vCPM placement plan look like on a real brief?
Fictional example
A science center membership launch in Louisville and Lexington
An unnamed science center with a planetarium sells annual family memberships in Louisville and Lexington, Kentucky. Its agency plans a fall Display campaign in English with image ads carrying the offer. No click is needed for the message to land, so the planner proposes vCPM.
The ad group holds an approved list of Kentucky news sites, family events calendars, parenting sites and astronomy and science education publishers, with no topics or keywords added. The default vCPM bid covers the list, and two regional news sites central to the brief get higher placement bids, each with its reason in the plan.
Before launch the planner confirms the ad formats work with vCPM and adds Active View columns. The account is not yet migrated, so the plan notes that Demand Gen would remove vCPM and that Google names Max Clicks as the alternative. No performance figures are implied.
How does PlacementGraph look at ad layout before a vCPM bid is set?
What should a buyer check before moving a placement campaign to vCPM?
Pre-launch checklist for vCPM on a placement list
- The campaign is a Display Network only campaign, and its Demand Gen migration status is known.
- The placement ad group has no topics or Display keywords that would widen the list.
- Each individual placement bid has a written reason.
- The ad formats in the campaign work with vCPM, so no ads are left unable to run.
- Viewable impressions, measurable rate, viewable rate and average viewable CPM columns are added to the report.
- A date is set to read the Where ads showed report and reconcile served sites with the list.
Google's Where ads showed page (opens in a new tab) says that report is not an exhaustive list of placements or a record of billing. For list mechanics, see the Display Network placements guide, and for the move itself, the Demand Gen migration guide.
Frequently asked questions
Is vCPM the same as Target CPM?
No. Google's bid strategy guide describes vCPM as a manual strategy that sets the highest amount you will pay for 1,000 viewable impressions on the Display Network. Target CPM sets an average you are willing to pay for every thousand impressions and optimizes bids to maximize the campaign's unique reach.
Am I charged for non-measurable impressions under vCPM?
Google's vCPM page says you pay for impressions measured as viewable, and also that a small portion of served impressions might be charged, without a breakdown of which ones. Compare the measurable cost and average viewable CPM columns with the invoice to see what was billed.
Why does the Viewable rate column show two dashes in Demand Gen?
Google's viewability metrics page says that for Demand Gen and most Video campaigns, excluding Video action campaigns, the column shows "--" in the unsegmented view. Apply the Ad format segment to see it, so viewability is judged within one format, such as Shorts or in-stream.
Should a vCPM bid be higher than a CPM bid would have been?
Google says that to keep costs and traffic at a CPM campaign's level, a vCPM bid might need to be higher than a standard CPM bid, and that buyers should experiment with a bid that fits the campaign's goals. It gives no ratio.
Sources
- Bid on viewable impressions using viewable CPM (opens in a new tab)Google Ads Help
- Active View (opens in a new tab)Google Ads Help
- Understanding viewability and Active View reporting metrics (opens in a new tab)Google Ads Help
- Understanding bidding basics (opens in a new tab)Google Ads Help
- Determine a bid strategy based on your goals (opens in a new tab)Google Ads Help
- Google Display Ads campaigns have a new home in Demand Gen (opens in a new tab)Google Ads Help
- Create a Video campaign (opens in a new tab)YouTube Help
- About placement targeting (opens in a new tab)Google Ads Help
- About combining content targeting types (opens in a new tab)Google Ads Help
- Leading Trade Groups Define “Made For Advertising” Websites (opens in a new tab)ANA (Association of National Advertisers), September 26, 2023
- About the Where ads showed report (opens in a new tab)Google Ads Help
Researched and written by PlacementGraph Research. Read how we research, source and update these pages. Corrections: diana@placementgraph.com.