In December 2024, Meta announced a next-generation personalized ad retrieval system called Andromeda.

Meta continuously tweaks its ad-serving algorithm. Performance marketers adapt to it and eventually find ways to game it. This cat-and-mouse game has been playing out for many years after Apple’s ATT changes back in 2021. The dark art of understanding and gaming Meta ads has been evolving.

The latest chapter in this dark art was flooding the Meta ad-account with so many creatives that ad creative volume became the name of the game. Because making creatives has become so cheap and because Meta is pushing for automated media buying, creative volume is increasing in orders of magnitude.

Creative Volume: Problem & Opportunity

To make ads more relavant, Meta needs advertisers to make a high volume of creaitve. However, high volume of ad creatives makes it difficult for Meta to offer better and more personalized ad recommendations. Meta’s ad system needs to evolve to find and score the most relevant ads for the user when they open the app. And Meta’s ad system must do it very quickly (in less than 300ms).

Meta needed a better way to select the "right" creatives, given the vastly increased scale of creatives. It also wanted to incentivize advertisers to make creatives that are more diverse and appealing to the users.

How Meta's Ad System Works?

Meta's ad system has two main stages:

Stage 1 : Retrieval

Meta has a massive inventory of hundreds of millions of ads. When a user loads their Facebook or Instagram feed, Meta’s ad system cannot possibly score every single ad for the user in real-time. The retrieval system's job is to instantly scan this entire inventory and retrieve a smaller, more manageable subset (e.g., the 1,000 most likely relevant ads) from the millions available. Kinda whittle down the list from 100s of millions of ads to a few 1000.

Stage 2: Ranking/Auction:

A second, more sophisticated ranking model predicts user and advertiser value to determine the final set of ads to be shown to the user. It takes that smaller subset of ads, say 1000, and carefully scores and ranks them to decide which single ad is the most relevant to show the user (in a specific ad slot).

What is Andromeda?

Andromeda is the next-generation ad retrieval system (stage 1).  Meta designed a neural net to work specifically on NVIDIA's Grace Hopper Superchip. It is a state of the art engineering of hardware and software on the latest chips to produce an ad retrieval system.

They trained this neural net on user data, higher-order interactions from people and ads data.

Andromeda has two goals:

1. Narrow down ad candidates: From millions of ads, whittle down to a much smaller number, like 1000, of relevant creatives for the user. This number could be anyone's guess, but 1000 seems reasonable.

2. Speed: Narrow down to that smaller list of ads very quickly. Likely in under 200ms or something ridiculous like this. Andromeda should work very fast in real-time to be useful to users of Facebook and Instagram.

Stop guessing what counts as “unique” creative.

Use Recharm’s Asset Similarity tool to instantly identify duplicate or near-identical creatives—and create ads that actually get picked by Meta’s retrieval system.
https://app.recharm.com/asset_similarity/

How Andromeda Works?

Andromeda first organizes ads in a unique tree-like structure, and then traverses this structure based on the user’s preferences and interactions from the past.

Organizing: When you upload a new ad creative, Meta analyzes various themes, sub-themes and organized the creative a tree based graph. The leaf node in this tree is the ad creative itself. Andromeda creates a hierarchical index of ads. It is essentially a sophisticated filing system for millions of ads. Comparing every ad against a user's profile would be very slow and expensive. That's why Andromeda organizes ads into a multi-layered structure, much like a family tree.

Ads that are visually and thematically very similar are grouped together and placed in the same node. For example, ten ads that use the same image but have slightly different headlines would be clustered tightly together in a low-level node, typically leaf nodes. This node, in turn, might be part of a larger branch representing a broader creative theme, like social proof.

Retrieval: When a user opens their app, Andromeda doesn't need to analyze every single ad. Instead, it navigates the hierarchy. It can quickly discard entire top-level branches (e.g., "humor-based ads") if they are not relevant to the user, thereby ignoring thousands of ads in a single step. It then drills down into more promising branches, eventually reaching the most relevant nodes.

Why Is Creative Similarity Important?

If you provide ten nearly identical ads, they are all filed under the same node. The retrieval model sees this node as representing a single creative concept. All visually similar ad creatives with the same thematic nodes are grouped together as a single entity. Meta has even called it Entity Id .

Creative similarity is the organizing principle for Andromeda's hierarchical index. By pre-sorting and clustering ads based on similarity, the system can focus and can become very fast. This is why providing visually and conceptually distinct ads is so critical; it creates new, valuable nodes in the index for the AI to work with.

What Is an Entity ID in Meta Ads?

Meta's Andromeda uses Entity IDs to group your ad creatives based on visual and thematic similarity. When you upload multiple ads, Andromeda doesn't treat each one independently, it clusters similar creatives under a shared Entity ID and treats them as a single concept.

This matters for advertisers because the number of unique Entity IDs in your account directly influences how many of your ads enter the retrieval stage. If ten of your ads share one Entity ID, only that single concept competes for retrieval — not ten individual ads.

Understanding Entity IDs helps you structure your creative strategy so Andromeda serves a wider range of your ads, rather than repeatedly surfacing your highest-spend or most-duplicated creative.

What Should Advertisers Do?

Advertisers should make creatives that helps Meta generate more unique Entity Ids. They should do two things:

1. Maximize the number of thematic nodes: During creative strategy, apply more themes and concepts while evaluating ad creatives against existing themes and concepts. The more variety you have, the better your ads are going to perform. Why ? More concepts means more nodes which in turn means that Andromeda will retrieve more of their ads. Hence, more of theri ads will participate in the auction and therefore have a chance of being shown to the user.

2. Reduce the number of visually similar creatives in a thematic node: Don't make too many ads that visually look the same for the same concept. Make ads that could be visually similar but for different audience segments or contexts. For example, the same product shot styled differently for a younger audience versus a professional one counts as two distinct creatives in Andromeda's index. The goal is to maximize the number of unique Entity IDs your account generates, not just the raw number of ads you upload.

Think of it this way: ten ads that look nearly identical give Meta one concept to work with. Ten ads that are visually and thematically distinct give Meta ten concepts, ten nodes in the index, and ten chances to retrieve and serve your ads to the right person at the right time.

Creative Diversity vs. Creative Volume

There's a common misconception that uploading more ads means more reach. With Andromeda, that's not how it works.

Running more ads is not the same as running diverse ads. If your creatives look visually or thematically similar; even if the copy, CTA, or headline differs; Andromeda clusters them under the same node and treats them as one concept. The result: a large portion of your ad inventory never makes it past the retrieval stage.

Andromeda actively deprioritises accounts where creatives look too similar. A smaller set of genuinely varied creatives; across visual style, theme, format, and concept; can outperform a large batch of near-duplicates. The goal isn't creative volume for its own sake. It's generating enough unique Entity IDs that Andromeda has distinct concepts to retrieve and send to auction.

How to Check Your Creative Similarity Score

Knowing your creatives are too similar is one thing — identifying which ones are the problem is another.

Recharm's Asset Similarity tool lets you instantly scan your creative library and flag duplicate or near-identical ads. Instead of guessing whether your latest batch of creatives is diverse enough for Andromeda's retrieval system, you get a clear, visual breakdown of which assets are too close to each other.

Use it to audit your existing library before launching a new campaign, or to validate new creatives before uploading them to Meta.

Check your creative similarity score on Recharm

Frequently Asked Questions

What is Meta Andromeda and how does it affect my ads?

Andromeda is Meta's ad retrieval system. It scans millions of ads and narrows them down to a smaller pool that gets sent to the ranking auction. If your creatives are too similar to each other, Andromeda groups them under one Entity ID and treats them as a single concept, meaning fewer of your ads make it to the auction. More diverse creatives means more Entity IDs, more retrieval, and more chances to be shown to users.

Does Meta Andromeda affect all ad placements including Stories and Reels?

Andromeda operates at the retrieval stage across Meta's ad inventory, which includes Feed, Stories, Reels, and all other placements. The retrieval and ranking logic applies regardless of placement. Creative diversity and Entity ID principles are relevant no matter where your ads are running.

How many ad creatives do I need for Meta Andromeda?

There is no magic number. The goal is not volume but diversity. Ten creatives that are visually and thematically distinct will outperform fifty creatives that look nearly identical. Focus on maximizing unique Entity IDs, not total creative count.

When did Meta launch Andromeda?

Meta announced Andromeda in December 2024 as part of a broader push to modernize its ad infrastructure. It was built to handle the explosion in ad creative volume that followed the shift toward automated media buying. As creative volume scaled into the hundreds of millions, Meta needed a retrieval system that could find the most relevant ads for each user in under 300ms. Andromeda was the answer.