Google Ads Display Expansion lets a Search campaign spend budget on the Google Display Network, and until the move to channel prioritization Google capped Display with a 50% budget allocation applied in the backend. From February 2027, those campaigns switch to it: you set Display to High or Low priority and can add a daily cap.
This guide is part of the Google Ads hub. The short recommendation: before February 2027, measure how much each Search campaign spends on Display, then set the Display Network to Low priority with a 50% allocation to keep today's behavior, or a lower cap (down to 0%) when Search results must come first. Campaigns on Target Impression Share lose Display delivery entirely.
What did the hidden 50% Display split do to Search campaigns?
Display Expansion on Search campaigns is a network setting that lets a Search campaign show ads on the Google Display Network, and before channel prioritization Google limited that Display spend with a 50% budget allocation applied in the backend that advertisers could not see or edit. So up to half a Search budget could go to Display unseen.
The Google Display Network is Google's network of websites, videos and apps where display ads appear. With Display Expansion on, a Search campaign can serve responsive display ads there, and Google offers the option to create image ads in the "Assets" section.
Google sells the setting with its own figures. The Display Expansion help page says, as of October 2026, that Search campaigns "that have spare search budgets and are opted into Display Expansion can deliver up to 15% more conversions at similar CPA to Search." It also claims 14% more conversion value when the core Search campaign uses Maximize conversion value or Target ROAS. Google gives no period or sample for either number, so treat them as vendor claims, not benchmarks.
What changes for Google Ads Display Expansion in February 2027?
In February 2027, Google Ads Display Expansion stops using its fixed backend split: every Search campaign that includes the Display Network moves automatically to channel prioritization and budget allocation. After the move, spend can shift between Google Search, search partners and the Display Network, based on the priority tiers and caps set on the campaign.
Officially confirmed, as of October 2026:
- October 14, 2026: Google announced the controls in a blog post by Tal Akabas, Director of Product Management, Google Ads: "Channel prioritization lets marketers decide where their budgets go first."
- October 15, 2026: a progressive rollout started, per the channel prioritization help page.
- February 2027: "Search campaigns with Display Expansion will automatically transition to channel prioritization," according to the Display Expansion help page.
- February 2027: Display stops serving on Search campaigns with Target Impression Share bidding.
- Before that: priorities you set take effect immediately.
Still open: Google does not say which settings a migrated campaign receives. PPC Land reported on October 24, 2026 that the help page does not state whether Google applies a 50% allocation automatically. My reading, not a Google statement: all channels default to High priority and a cap only exists on Low priority channels, so a campaign left on the defaults would have no Display cap. Setting the tier yourself removes that risk.
How do High priority, Low priority and budget allocation work?
Channel prioritization is a Google Ads setting that ranks each channel in a campaign as High or Low priority, so Google spends on High priority channels first. Budget allocation is an optional best-effort cap on a Low priority channel, set as a percentage of the campaign's average daily budget, that limits how much that channel can spend per day.
Search campaign channels are Google Search, search partners and the Display Network. The rules, per the help page as of October 2026:
- Default: all channels start at High priority.
- Levels: account default per campaign type, "Use campaign-level settings," or a shared budget.
- Cap math: Google's example: 5% of a $1,000 average daily budget, about $50 per day, reset daily.
- Best effort: Google says "this isn't a guarantee."
- Zero: at 0%, Google will not spend on that channel.
| Bid strategy | Effect of High and Low priority | Effect of a budget allocation cap |
|---|---|---|
| Target CPA, Target ROAS, Target CPC, not limited by budget | No change to spend distribution | Still applies |
| Target CPA, Target ROAS, Target CPC, limited by budget | High priority first; Low priority gets budget when it can hit the target | Applies |
| Maximize conversions, Maximize conversion value, Maximize clicks, Manual CPC | High priority first, remainder to Low priority | Applies |
| Target Impression Share | High priority first | Display stops serving from February 2027 |
Which channel priority setting fits your goal?
The right channel priority setting depends on what the Search campaign must deliver: protect Search volume, keep today's behavior, or buy extra reach. Display at Low priority with a cap is the safer default for most lead and sales campaigns, while High priority without a cap only fits campaigns where Display has proven it converts at your target.
| Situation | Display Network priority | Budget allocation | Why |
|---|---|---|---|
| No network data yet | Low | 50% | Google's way to keep the current setup |
| Display converts worse, Search is budget limited | Low | Below the measured Display share | Search spends first |
| Display leads fail your quality check | Low, or untick the network | 0% | No Display spend |
| Display converts at target, budget left over | High | None | Equal terms |
| Target Impression Share bidding | Not applicable | Not applicable | Display ends February 2027; use a separate campaign |
Worked example (hypothetical numbers). A Search campaign has a $200 average daily budget, and Display took 35% of cost (about $70 per day) at double the Search cost per conversion. A 50% cap allows up to $100, so nothing changes. A 15% cap targets $30, freeing about $40 per day for Google Search if Search auctions can use it.
What should you do in each Search campaign before February 2027?
Before February 2027, each Search campaign with Display Expansion needs a measured network split, a priority tier and cap that fit its goal, and those settings saved before Google migrates it. Measure first: the right cap depends on how much Display takes today and what it returns.
- Open the Campaigns table. Filter to Search campaigns with Display included.
- Apply the segment. Choose "Network (with search partners)," per Google's segments help page.
- Pick a long date range. Cover one full conversion cycle.
- Calculate the Display share. Divide Display cost by total cost, then compare cost per conversion under a fitting attribution model.
- Open the network settings. Click "View network settings" under "Networks."
- Choose the level. Account default or "Use campaign-level settings."
- Set Display to "Low priority." Enter 50% or your measured cap.
- Recheck in one to two weeks. Segment by network again.
As of October 2026, the help page says manager accounts cannot set these controls and that Google Ads API and Google Ads Editor support is "coming soon." The same controls exist for the Performance Max campaign type.
Common mistakes with Display Expansion and channel prioritization
The most common mistakes with Display Expansion and channel prioritization come from treating the February 2027 migration as a default you can ignore, or from reading the budget allocation cap as a hard limit. Each one lets Display take budget that Search could have spent on high intent queries, or hides where the money went.
- Waiting for the automatic migration. Google does not say what a migrated campaign gets, and the default tier is High. Set the tier and cap yourself before February 2027.
- Treating the cap as a hard limit. Budget allocation is best effort and can be exceeded on single days. Judge it on weekly or monthly network data.
- Expecting tiers to change a Target CPA campaign that is not limited by budget. Google says priorities have no effect there. Use a cap instead, or check whether the target or budget is the real limit, as in the guide to Target ROAS.
- Forgetting Target Impression Share campaigns. Display stops serving on them in February 2027. If Display brought useful conversions, rebuild that reach in its own campaign.
- Comparing networks on blended numbers. A low campaign cost per conversion can hide weak Display leads. Segment by network, as part of a regular Google Ads audit, and check what each click really costs in the guide to Google Ads cost.
