How Meta's DIA (Dynamic Inclusive Allocation) Works Explained

Quick Answer

Dynamic Inclusive Allocation (DIA) is the budget reallocation engine inside Meta's CBO campaigns. It runs every 15 minutes and shifts budget between ad sets based on marginal expected value per dollar, not absolute performance. The "inclusive" part means DIA is biased to keep underperforming ad sets on small spend rather than starving them entirely — preserving exploration paths that might pay off later.

The Mechanism Explained

DIA solves a constrained optimisation problem every quarter-hour: given the campaign's daily budget, how should the next 15 minutes of spend be split across N ad sets to maximise expected total value?

For each ad set, DIA estimates:

Current marginal cost per result — what would the next $1 buy?
Saturation curve — how does that marginal cost change as spend rises within the day?
Confidence in the estimate — wide CI ad sets get exploration weight, narrow CI ones get exploitation weight

DIA then runs a water-filling algorithm: pour budget into the lowest-marginal-cost ad set until its saturation curve crosses the next ad set, then split. The "inclusive" tilt floors each ad set at roughly 5% of its expected fair share even when its marginal cost is materially worse — Meta justified this in 2021 docs as preventing learning collapse.

In 2026, DIA also factors in diversification value: if two ad sets are reaching overlapping audiences, DIA will deprioritise one to avoid cannibalisation, which it didn't do prior to 2023.

Practical Implication

In CBO, do not interpret a "winning" ad set as the one DIA gave most spend to. DIA reallocates based on marginal cost, which means once your top ad set saturates, additional spend goes to the second-best one. Ad set ranking by spend is misleading — rank by CPA instead, and watch hour-over-hour, not day-over-day.

The corollary: starving the bottom ad set by setting an aggressive minimum spend rule fights DIA. DIA is doing it for a reason.

Real Numbers

DIA reallocation cadence: every 15 minutes (was 60 mins pre-2022)
Inclusive floor: ~5% of fair share per active ad set
Average CBO campaign sees 3-7 reallocation events per day at scale

FAQs

Q: Does ABO bypass DIA?
Yes — ABO sets per-ad-set budgets that DIA cannot touch.

Q: Can I see DIA's reallocations?
Only indirectly via the spend/results breakdown by hour in Ads Manager.

Q: Does DIA work across campaigns?
No. DIA operates within a single CBO campaign only. Cross-campaign moves are your job.

Q: Why does DIA sometimes shift budget back to a 'bad' ad set?
Either the saturation curve flipped or the model regained confidence after a noisy hour.

Q: Can I disable inclusive allocation?
Not directly. But minimum/maximum spend rules at ad set level constrain DIA's range.

Pix-Vu

DIA can only allocate budget to ad sets it has high confidence in — and confidence comes from creative density and clean conversion signal. Pix-Vu generates the creative supply that lets every ad set in your CBO have enough variants to find a winner. Free to start at https://pix-vu.com.