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Meta Andromeda groups similar creatives under hidden Entity IDs. Your 200 ads may be treated as 20. Here is what creates a genuinely new entity.
Behind the scenes, Meta groups similar creatives under a hidden identifier most advertisers never see. It is called the Entity ID, and it is distinct from the two IDs you likely already know.
Every ad in your account carries three identifiers.
Ad ID: the wrapper around each individual ad. It is the one you see in Ads Manager, the one you duplicate, pause, or kill.
Creative ID: tied to each asset you upload. Every image, every video, every carousel gets one.
Entity ID: the invisible grouping that Meta's retrieval engine uses to decide which ads are functionally the same.
And here is the uncomfortable truth: the Entity ID is the one that matters most.
Meta's Andromeda system, described by the company as "a personalized ads retrieval engine" that selects from "tens of millions of ad candidates into a few thousand relevant ad candidates," uses a hierarchical index to organize ads into layers. The system was designed specifically to handle what Meta calls "exponential ad creatives growth" driven by Advantage+ and generative AI tools.
But this indexing comes with an implicit grouping mechanism. When multiple creatives share the same visual structure, the same opening sequence, or the same talent, Andromeda's retrieval stage sees them as essentially one option and allocates delivery accordingly.
Everything sharing one Entity ID also shares learnings, delivery patterns, and cost efficiency. That means your 200 ads are not competing independently in the auction. They are stacked on top of each other, cannibalizing the same audience cohort rather than reaching anyone new. This is exactly the dynamic we covered in our piece on creative diversity in Meta advertising: the delivery system penalizes redundancy, and Entity ID overlap is the mechanism underneath.
Meta's internal grouping is aggressive. The following changes do not create a new Entity ID:
Taking the same visual and applying a new headline. Shooting the same product from a slightly different angle or with different lighting. Using the same creator with the same intro sequence in the same setting.
These variations look different to you. To the retrieval engine, they are the same node in the hierarchical index, the same slot in the system. That is 20 ads occupying the space of one.
A new Entity ID only spins up when something structurally distinct changes:
Format. A static image and a video are not the same entity. Neither is a carousel. Switching formats signals a genuinely different creative experience to the retrieval system.
Context. A product shot on a flat white background is not the same entity as the same product shown on a model in a lifestyle scene. The visual context changes enough that the retrieval model treats them as distinct options.
Talent. A new face, a new voice, a new creator: these trigger new entities. The system recognizes that a different person on screen creates a fundamentally different ad experience, even if the product remains the same.
This is what "creative is the new targeting" actually means at the platform level. Every new Entity ID gets its own learning phase and its own pocket of audience, because Meta's system, as the Andromeda paper explicitly states, was designed "to deliver a more diverse set of ad candidates" on the basis that "increased ad diversity can improve people's experience with ads and drive better advertiser outcomes." This insight is also why the Wilow Creative Leaderboard ranks by individual creative performance rather than aggregated ad set data: if Meta sees your ads as distinct entities, your analytics should too.
Meta does not surface Entity IDs directly. Company representatives routinely describe them as internal-only infrastructure. But three metrics are emerging as proxies that advertisers can actually use:
Creative Similarity. The closest available read on Entity ID overlap. It estimates how many of your ads are functionally competing for the same retrieval slots. A high similarity score means your creatives are stacked, and your effective reach is a fraction of what your ad count suggests.
Creative Themes. An indication of how Meta's system is bucketing your ads into topic clusters. If all your themes sit under one bucket, the retrieval stage never branches out to new audience segments.
Creative Fatigue. A signal that your ads have exhausted their addressable audience within their Entity ID group. When this metric rises, further spend on that entity delivers diminishing returns, not because the creative is bad, but because the cohort it can reach has already been saturated.
These are not vanity metrics. A high Creative Similarity reading on an account running hundreds of ads is a structural problem: volume without diversity, spend without reach.
The instinct when performance stalls is to produce more ads. More variations. More headlines. More versions of the same asset with minor tweaks. That instinct is what the Entity ID problem punishes.
The shift is from volume thinking to entity thinking. Instead of asking "how many ads am I running," ask:
How many distinct formats do I have live right now? How many different visual contexts: studio, lifestyle, UGC, screen recording? How many different faces or voices appear in my current ad set?
The number that matters is not the ad count in your Ads Manager. It is the number of Entity IDs your account is actually generating, and that number is almost certainly smaller than you think.
Sources: Meta Engineering, "Meta Andromeda: Supercharging Advantage+ automation with the next-gen personalized ads retrieval engine" (December 2024). Quotes drawn directly from Meta's published documentation on the Andromeda retrieval system, hierarchical indexing, and ad diversity objectives.