Google said that view-through conversion bidding in Demand Gen will become video-only, so image assets will no longer be eligible for view-through conversion bidding. Google also said view-through conversion optimisation will expand beyond YouTube and the Discover feed onto the Google Display Network, and that display video ads will shift from cost-per-click billing to cost-per-thousand-impressions. Search Engine Land reported the update on 17 August 2026. Google described the rollout only as happening over the coming months and did not publish exact dates.
The three changes Google announced for Demand Gen
The announcement covers three linked changes to how Demand Gen handles view-through conversions, which are conversions credited to an ad that was seen rather than clicked.
- View-through conversion bidding becomes video-only. Image assets stop being eligible for view-through conversion bidding. Google's wording is that "while image asset view-through conversions will still be reported as secondary conversions in existing campaigns, they will no longer be eligible for bidding".
- View-through conversion optimisation expands onto the Google Display Network. It previously applied on YouTube and the Discover feed. The Display Network is added to that surface list.
- Display video ads move from CPC to CPM. Billing for display video ads changes from cost-per-click to cost-per-thousand-impressions.
On defaults, Google said view-through conversion optimisation will be enabled by default for all newly created Demand Gen campaigns, and that existing campaigns will retain their current settings and will not automatically opt in. The practical read is that anyone building a new Demand Gen campaign after the rollout has to opt out deliberately if they do not want it, while campaigns already running are left where their owner set them.
Reported but not bid on: the distinction at the heart of this Demand Gen change
The most consequential line in Google's wording is the narrow one. Image asset view-through conversions do not disappear. They keep being reported as secondary conversions. What they lose is eligibility for bidding, which means Smart Bidding stops treating them as a signal it should chase.
Those are two different systems doing two different jobs, and it is worth separating them. Reporting is the record of what the account is credited with. Bidding is the instruction set the auction machinery optimises against. Until now, in Demand Gen, an image impression that preceded a conversion could feed both. After the change, it feeds only the first.
That gap is where the reading of performance goes wrong, and the mechanism is unglamorous. A manager opens the campaign view, sees a conversion column that still includes image asset view-through conversions, and concludes the campaign is producing at roughly the same rate as last month. Meanwhile the bidding system, which no longer counts those events, has quietly re-weighted spend toward whatever it still gets credit for. The reported total holds up. The composition underneath it changes. Nothing in the interface announces that the two numbers have stopped describing the same thing.
The risk is concentrated in accounts that judge Demand Gen on blended conversion totals, which is a common setup in awareness-led media plans where a single conversion column is the reported number and the detail sits a click away. If the total is the only figure anybody looks at, the change is invisible for as long as the total holds. It becomes visible later, usually when someone notices that click volume or lead counts moved in a direction the conversion column did not predict.
What changes and what it means for advertisers
The table below sets out the announced changes against the practical consequence for an advertiser running Demand Gen. Everything in the left column comes from Google's announcement as reported by Search Engine Land. The right column is reasoning about the consequence, not a Google statement.
| What Google announced | What it means for advertisers |
|---|---|
| View-through conversion bidding becomes video-only; image assets are no longer eligible | Smart Bidding stops optimising toward image-driven view-through events, so the mix of what the auction chases shifts toward video |
| Image asset view-through conversions keep being reported as secondary conversions | The reported conversion figure can stay flat while the bidding signal behind it has narrowed, so a blended total is no longer a reliable read on what the campaign is optimising for |
| View-through conversion optimisation expands onto the Google Display Network | Demand Gen delivery on Display now carries view-through optimisation as well, widening where these conversions can be generated |
| Display video ads move from cost-per-click to cost-per-thousand-impressions | The unit of cost changes from an action to an impression, so cost per outcome depends on view-to-action rates rather than being fixed at the click |
| New Demand Gen campaigns are opted in by default; existing campaigns keep their current settings | Campaigns built after the rollout need a deliberate opt-out if the setting is unwanted; running campaigns are not changed for you |
What the CPC to CPM switch does to Demand Gen unit economics
Under cost-per-click billing, an advertiser pays when someone acts. The impression is free, and the cost of a wasted view is zero. Under cost-per-thousand-impressions, the advertiser pays for delivery, and the click becomes a free consequence of a paid impression. Google's change moves display video ads in Demand Gen from the first model to the second.
The arithmetic follows from that and needs no new data. On CPC, effective cost per acquisition equals the cost per click divided by the click-to-conversion rate. On CPM, it equals the cost per thousand impressions divided by the number of conversions those thousand impressions produce, which folds view-to-click and click-to-conversion into one chain. The number of moving parts in the cost calculation goes up by one, and the part that was previously fixed, the price of an action, becomes variable.
What that means in practice depends entirely on creative and placement quality, and Google published nothing about the size of the effect. Strong video creative that earns attention gets cheaper under CPM, because the advertiser now pays the same for a thousand impressions whether or not they perform. Weak creative gets more expensive for exactly the same reason. CPC billing absorbed some of the cost of a poor asset. CPM does not.
The second-order point is about budget pacing. A CPM-billed placement spends its budget on delivery, which is easier for the system to find than clicks are. Campaigns that used to be click-limited can become delivery-limited, which usually shows up as faster spend at the start of the day. That is a reasonable thing to watch after the rollout reaches an account, and it is measurable from the campaign's own daily spend curve rather than from anything Google needs to confirm. Advertisers who want a second reading independent of the ad platform can compare the pattern against session and event data in their analytics setup.
Which Demand Gen campaigns are affected and which are not
Google drew the line at campaign creation date, not at account or vertical. New Demand Gen campaigns get view-through conversion optimisation on by default. Existing Demand Gen campaigns keep their current settings and are not automatically opted in.
That is a narrower default than it first sounds, and it is worth being precise about it. If a campaign is running today with view-through optimisation off, Google said it stays off. If it is running with the setting on, it stays on. The default applies to campaigns that do not exist yet.
The image asset bidding change is a different matter. Google's wording refers to image asset view-through conversions continuing to be reported as secondary conversions in existing campaigns, which indicates the bidding eligibility change reaches existing campaigns too. So an account can be in the position of having no setting changed while the meaning of its numbers has changed. Both statements are true at once, and conflating them is the easiest mistake to make when reading this announcement.
What to check in your own Demand Gen campaigns
None of this requires action before the rollout arrives, because Google gave no dates. It does reward knowing where your account currently stands, so that a change is recognisable when it happens.
- Find out which conversion actions are primary and which are secondary. In Google Ads this sits under Goals, then Conversions, then Summary, where each conversion action carries a primary or secondary designation. Only primary actions feed bidding. If view-through conversions have been sitting in the primary set, the change to image asset eligibility matters more in that account than in one where they were already secondary.
- Separate the conversion column you report on from the one you optimise on. A blended total that mixes click-through and view-through conversions will not show this change. Segmenting by conversion action, or reporting the primary-only column alongside the all-conversions column, will.
- Record a baseline for image-heavy Demand Gen campaigns. Cost per click, click volume and conversion mix over a stable recent period give a comparison point. Without one, any post-rollout movement is arguable in both directions.
- Look at the ratio of image to video assets in each campaign. Campaigns leaning on image assets carry more exposure to the bidding change than video-led ones, which is a straightforward consequence of the eligibility rule rather than a prediction.
- Check daily spend pacing on campaigns that serve display video. A shift toward impression-based billing can change how quickly a budget is consumed within the day.
Accounts that treat Demand Gen as a companion to search activity should also look at how the two are read together, because a change in one column's meaning tends to show up first as an unexplained gap between platforms. Teams reviewing their wider Google Ads setup can fold this into the same pass, and anyone running video-led Demand Gen has an obvious overlap with their YouTube advertising planning, since video is the asset type that keeps view-through bidding eligibility.
What Google did not say about this Demand Gen update
Being clear about the gaps is part of reading an announcement like this one.
- No dates. Google said the changes roll out over the coming months. There is no start date, no completion date and no phased schedule in the announcement.
- No magnitude. Google gave no figure for how much reported conversions, cost per click or cost per acquisition might move. Any number attached to this change at this stage is somebody's estimate.
- No statement on future migration. Google said existing campaigns will not automatically opt in. It did not say whether existing campaigns will be migrated later, and the absence of a commitment either way is not evidence of either outcome.
- No detail on the Display Network mechanics. The announcement says view-through conversion optimisation expands onto the Google Display Network. It does not describe placement controls, exclusions or reporting breakouts for that surface.
- No regional detail. Nothing in the reporting distinguishes markets, so there is no basis for saying the rollout order differs by country.
The honest limit on what can be concluded today is this: the direction of the change is clear, the timing is not, and the size of the effect on any individual account depends on that account's asset mix and conversion setup rather than on anything published so far.
What this means for Thai marketers
Demand Gen has become the default home for awareness budgets that used to sit in Discovery campaigns, and in Thailand that pattern is pronounced because awareness spend is a large share of many media plans. A change to how Demand Gen bids and bills lands on a bigger slice of the local budget than the same change would in a market weighted toward search.
The billing switch is the part with the sharpest local edge. Thailand has historically been a low-CPC market, and cheap clicks were the favourable side of the trade for advertisers buying attention there. Moving display video ads to cost-per-thousand-impressions removes that advantage on the affected placement, because the price is now set by delivery rather than by an action that happened to be inexpensive locally. Whether the net cost per outcome rises or falls depends on view-to-action rates, which vary by creative and audience and are not something the announcement addresses.
Neither Google nor Search Engine Land said anything specific about Thailand, and nothing here should be read as a country-level statement from either. The reasoning is about how a global product change meets a local cost structure, and Thai advertisers are in a good position to test it against their own numbers once the rollout reaches their accounts.
FAQ: Demand Gen view-through conversion changes
Do I have to do anything right now?
No. Google gave no dates and existing campaigns keep their current settings, so there is no deadline to act against. The useful preparation is knowing which of your conversion actions are primary, which are secondary, and how image-heavy your Demand Gen campaigns are, so that any movement after the rollout is measurable against a baseline you recorded first.
When does this happen?
Google did not say. The announcement describes the rollout as happening over the coming months, with no start date and no completion date published. Anyone quoting a specific date for this change is not quoting Google.
Will my existing Demand Gen campaigns change?
Your settings will not change, but the meaning of one of your numbers will. Google said existing campaigns retain their current settings and will not be automatically opted in to view-through conversion optimisation. Separately, image asset view-through conversions lose bidding eligibility while continuing to be reported as secondary conversions, so an existing campaign can keep every setting it has and still have a bidding signal that has narrowed.
Will my reported conversions drop?
Not because of this change, based on what Google described. Image asset view-through conversions continue to be reported as secondary conversions, so they stay in the reporting. What changes is that they no longer influence bidding, which can move the underlying performance without moving the reported total.
Does the CPM switch mean display video gets more expensive?
Google published no figures, so the honest answer is that it depends on the creative. Cost-per-thousand-impressions billing charges for delivery rather than for clicks, which lowers effective cost per outcome for assets that convert attention well and raises it for assets that do not. The direction for any single campaign is only knowable from that campaign's own view-to-action rates.
If you want a second pair of eyes on how your Demand Gen campaigns are set up before the rollout reaches them, particularly on which conversion actions are feeding bidding and which are only feeding reports, Relevant Audience can run that check.
