Across a benchmark dataset of 14,197 US accounts, Fibbler reported average CPA on Search at $48.96 versus $75.51 on Display. That gap has been sitting in plain sight for years, yet Google Ads forced a binary: opt in to Display inside your Search campaign, or opt out entirely. No middle ground. No cap. No funding order.

That changed on October 14, when Google announced channel prioritization and budget allocation controls across Search, Shopping, Performance Max, and Demand Gen campaigns. You can now mark each channel (Google Search, Search partners, Display) as High or Low priority, and campaigns fully fund high-priority channels before anything flows downstream. Low-priority channels get a percentage-based budget cap on top of that.

Budget Steering, Not a Performance Verdict

Google frames this as spending guidance, not a recommendation about which channel is better. High priority means funded first. It doesn't mean it will outperform. And here's the part most teams will miss: if your Target CPA or Target ROAS campaigns aren't hitting their daily budget, priority alone generally won't change where spend goes. The budget allocation cap is the lever that actually redirects dollars in unconstrained campaigns. If your campaigns rarely exhaust daily budgets, skip the priority toggle and go straight to the cap.

There's a forcing function baked in. Starting February 2027, Search campaigns with Display turned on lose their current spend allocation setup. Google's guidance: set the Google Display Network to Low priority with a 50% budget allocation before that date to preserve your existing configuration. Doing nothing is a decision. Pull a list of every affected campaign now and decide: turn Display off, set it to Low with a 50% cap, or lower the cap further to run a tighter test.

Run It This Week: A Channel Prioritization Test

Setup:

Success = Search CPA holds within 5% of baseline; partner/Display conversions show a measurable share of qualified pipeline at a CPA you'd accept standalone. Guardrails = if blended CPA rises more than 15% in week one, pause the low-priority channels and diagnose. Stop-loss = if qualified conversion rate from partner/Display inventory drops below 40% of Search's rate after two weeks, kill the test and reallocate.

One thing to watch: Google's own data on Search partners claims 11% more conversions for volume-focused Smart Bidding among advertisers spending at least 5% of budget on partners in unconstrained campaigns. That's a specific cohort. Don't treat it as a universal promise. Validate with your own pipeline data before scaling.

Blended campaign KPIs are now actively dangerous. Three channels inside one campaign, each with different priority levels and caps, means the campaign-level CPA is an average of things that shouldn't be averaged. Report by network. Compare Search CPA to partner CPA to Display CPA independently, then trace each to downstream stages: did those conversions become qualified meetings? Did they progress to pipeline?

The same Fibbler benchmark data shows Search conversion rates averaging 3.75% versus Display at 0.77%. That's directional, not a verdict on your account. Display may earn its place for remarketing or assisted conversions even with lower direct conversion rates. But you won't know unless you segment and measure downstream. And if you're running Display for demand creation or remarketing, a dedicated campaign with its own creative, bidding, and goals will always give you cleaner signal than a cap inside a Search campaign. Prioritization is useful for controlled testing; it's not a substitute for campaign architecture.

The cap is best-effort, not a hard wall. Search Engine Land's coverage and Google's own documentation make clear this is a guide, not a guarantee. Check network-level reporting after you set it. If spend drifts past your cap consistently, you likely have a budget constraint interaction with Smart Bidding and need to diagnose before trusting the number.

Channel prioritization replaces a checkbox with a dial. That's progress. But a dial without a measurement plan is just a more sophisticated way to lose track of where your budget went. Set the priorities, set the caps, segment the reporting, and judge every channel on what it contributes to qualified pipeline, not on what the campaign dashboard blends together.