Remarketing Lists vs Similar Segments: What Survived the Sunset
In short: These two used to be a pipeline: remarketing lists collected your visitors, and similar segments derived resembling strangers from them. Half of that pipeline is gone - Google retired similar segments in 2023 and folded the expansion job into automated features - while remarketing lists remain central to retargeting and RLSA. The lists survived because they are inputs; the derived segments died because they were outputs automation could replace. Retarget with lists; for lookalike-style prospecting, seed optimized targeting or Demand Gen lookalikes with those same lists.
By the AdFlint research team · Fact-checked against current Google and Meta platform behavior · Last reviewed July 2026
Remarketing Lists
Audience lists built from people who already visited your site, used your app, or watched your videos, applied for targeting or bid adjustments in Google Ads.
A Google tag or linked Analytics property collects visitors into rule-based lists - all users, cart abandoners, a specific URL path - which you apply to Display, Video, Demand Gen, or Search campaigns as RLSA. Lists must clear minimum sizes before they serve. Most advertisers build one catch-all list and stop; segmenting by page depth and recency is where the performance difference actually lives.
Full definitionSimilar Segments
Google's retired audience expansion feature, which generated lookalike-style segments from a seed list before being removed in 2023 in favor of automated targeting.
Similar segments once derived a resembling audience automatically from a remarketing or Customer Match seed, and Google sunset them so campaign-level automation could do that expansion instead. Your seed lists remain valuable as signals feeding optimized targeting and Smart Bidding rather than as sources for a derived list. Advertisers still hunting for the setting almost always want optimized targeting or Customer Match.
Full definitionSide by side.
The differences that actually change what happens in your account.
| Remarketing Lists | Similar Segments | |
|---|---|---|
| Status in mid-2026 | Alive and central to retargeting and RLSA. | Retired in 2023 - the option is gone from the interface. |
| Who it reached | People who actually visited your site, watched your videos, or used your app. | Strangers who statistically resembled those people. |
| The job it did | Retention-side - recover and re-engage known visitors. | Prospecting-side - scale beyond the list to fresh lookalikes. |
| What does that job now | Still remarketing lists - nothing replaced them. | Optimized targeting on Display and Video, lookalike segments on Demand Gen, Smart Bidding signals on Search. |
| Your control over it | Rules, recency windows, and membership duration are all yours to define. | Was a black box then, and its successors are even less inspectable. |
| Reporting today | Each list is a row you can judge, bid on, and exclude. | Successor expansion blends into ad group totals with no lookalike row to evaluate. |
What actually separates them.
Remarketing lists are still selectable, while similar segments are gone - and ad groups that leaned on them lost that reach when the segments were removed, not when anyone touched the account.
Lists are inputs and similar segments were outputs, which is exactly why one survived the sunset and the other did not.
Better-segmented seed lists used to sharpen your similar segments; today the same hygiene sharpens optimized targeting and Smart Bidding instead, so the work is unchanged but the lever moved.
On Search, lists still power RLSA bid adjustments, while the Search flavor of similar audiences went away with the rest and Smart Bidding absorbed the role.
A remarketing list works as an exclusion, while similar segments never did that job reliably because membership was a model's guess rather than an observed visit.
Which one should you use?
Use Remarketing Lists when
- You want cart abandoners, lapsed visitors, or product viewers brought back with tailored messages.
- You need RLSA bid adjustments when past visitors search again.
- You want exclusion pools - past converters carved out of prospecting budgets.
- You are investing in seed quality so automated expansion has something clean to learn from.
Use Similar Segments when
- You are auditing an account whose performance history leaned on similar audiences and need to explain what changed after 2023.
- An old playbook says to build a converter list and target its similar audience, and you need the current translation.
- You want resembling-stranger prospecting today, which now means optimized targeting or Demand Gen lookalikes seeded by your lists.
- You are comparing platforms and need to know Google no longer offers a general lookalike product while others still market the concept.
Common questions.
What happened to my similar audiences segments?
Google removed similar audiences in 2023. Historical performance stays in old reports, but the segments stopped populating and serving, and they cannot be added to targeting anymore. Any ad group that depended on them simply lost that reach - the fix is enabling the automated expansion features that inherited the job.
How do I do lookalike prospecting on Google now?
Three routes, by campaign type. On Display and Video, enable optimized targeting with your remarketing and Customer Match lists attached as signals. On Demand Gen, build lookalike segments from a seed list, keeping in mind that since early 2026 they default to acting as a signal rather than a hard boundary. On Search, there is no lookalike product - Smart Bidding weighs your lists as auction signals instead.
Do bigger remarketing lists still help expansion?
Yes, and quality matters as much as size. The automated features that replaced similar segments read your lists as seeds, so a well-segmented converter list steers expansion toward better prospects than a catch-all all-visitors pool. The old advice about feeding lookalikes clean seeds transferred intact to optimized targeting.
Should I restructure my account now that similar segments are gone?
Only where structure existed to hold them. Ad groups that existed purely to target a similar segment should have their budget folded into prospecting with optimized targeting enabled. Keep remarketing in its own campaigns regardless, so warm-audience performance stays readable instead of blending into expansion traffic.
Or stop choosing between them.
AdFlint picks the setting, writes the ads, and keeps optimizing inside the Google and Meta accounts you already own.
Related comparisons
- Affinity Audiences vs In-Market Audiences
- Custom Segments vs In-Market Audiences
- Customer Match vs In-Market Audiences
- In-Market Audiences vs Remarketing Lists
- In-Market Audiences vs Similar Segments
- Demographic Targeting vs In-Market Audiences
- In-Market Audiences vs Life Events Targeting
- In-Market Audiences vs Optimized Targeting