Google Ads RLSA: Remarketing Lists for Search Ads (And Why You Should Use Them)

Most operators think of remarketing as a display thing — show banner ads to people who visited your site. RLSA (Remarketing Lists for Search Ads) is different and more powerful: it adjusts your search ad behavior based on whether the user has visited your site before.

If you're running Google Search Ads without RLSA strategy, you're missing one of the most ROAS-positive optimizations available.

What RLSA does

RLSA lets you:

• Bid differently on search keywords based on whether the user is in a remarketing audience.
• Show different ads to past visitors than to first-time searchers.
• Show ads on broader keywords to past visitors that you wouldn't show to cold traffic.

In effect: a user who's been to your site is treated differently when they search than a user who hasn't.

Why this matters

Past visitors:

• Convert at 2-5x the rate of cold traffic on search ads.
• Are willing to spend more (you've already attracted them).
• Are more profitable to bid aggressively on.

Without RLSA: you bid the same on a competitive keyword whether the searcher is a past customer or a complete stranger. Often you can't profitably bid on broad/generic terms for cold traffic — but for past visitors, those same terms convert at much higher rates.

RLSA setup

Step 1: Build remarketing audiences

In Google Ads → Tools → Audience Manager. Create:

• All website visitors (last 30 days).
• Product page viewers (last 30 days).
• Cart abandoners (last 14 days).
• Past purchasers (last 90 days).
• Engaged visitors (3+ pages, 2+ minute session).

Source from Google Analytics if linked, or from Google Ads tag directly.

Each audience needs 1,000+ users to be usable for RLSA. Smaller audiences are too small for the algorithm to use.

Step 2: Add audiences to search campaigns

For each search campaign:

• Audiences → "Targeting and bidding" or "Observation."

Observation mode: ads serve to everyone, but you can see how each audience performs and adjust bids per audience.

Targeting mode: ads serve only to users in the audience.

For most use cases: start with Observation mode. Get data on how each audience performs. Then layer in adjustments.

Step 3: Add bid adjustments

In Observation mode, set bid modifiers per audience:

• All website visitors (last 30 days): +20% bid.
• Product page viewers: +35% bid.
• Cart abandoners: +50% bid.
• Past purchasers: +30% bid.

The exact number depends on how much each audience converts above baseline.

RLSA strategies

Strategy 1: Bid up on past visitors

Standard approach. Same campaigns, higher bids when the user is in a remarketing audience.

Implementation: Observation mode + bid modifier.

Result: capture more conversions from users already familiar with your brand.

Strategy 2: New campaign for past visitors only

Create a separate campaign:

• Targeting: only users in remarketing audiences.
• Keywords: broader, more generic, more aspirational than your standard search campaigns.
• Bid: higher than standard campaigns.

Why: keywords like "best running shoes" are usually too competitive for cold-traffic search. But for past visitors who already know your brand, they convert.

Strategy 3: Different ads for past visitors

Same campaigns, but custom ads served to remarketing audiences:

• "Welcome back" messaging.
• Reminder of items they viewed.
• Specific offers (free shipping, discount).

Implementation: requires ad customizers or separate ad groups for the audience.

Strategy 4: Excluding past customers from acquisition campaigns

Reverse RLSA: don't show prospecting search ads to existing customers.

Why: they don't need a "discover us" ad. They need a different message (cross-sell, upsell, retention).

Implementation: add past purchasers as a negative audience in acquisition campaigns.

Building tiered RLSA bid adjustments

A common implementation:

| Audience | Bid Modifier | Why | |---|---|---| | All visitors (30 day) | +20% | Some intent | | Product viewers (30 day) | +40% | Higher intent | | Cart abandoners (14 day) | +75% | Highest intent | | Past purchasers (90 day) | +30% | Buy again, but different goal | | Past purchasers (180 day) | -10% | Less recent, less intent |

Each tier reflects the conversion rate of that audience above your baseline.

Smart Bidding and RLSA

If you're running Smart Bidding (Target ROAS, Maximize Conversions), the algorithm already uses audience data implicitly. But:

• Adding audiences in Observation mode still helps the algorithm by giving explicit signals.
• Manual bid modifiers are ignored under Smart Bidding (Google calculates bids automatically).
• Targeting mode (vs Observation) still works — the algorithm respects the targeting filter.

For Smart Bidding accounts, focus on:

• Adding audiences to all campaigns (Observation mode).
• Creating dedicated RLSA-targeted campaigns for broader keywords.
• Letting Smart Bidding handle the actual bid math.

Customer Match: another remarketing flavor

Customer Match: upload customer email lists to Google. Google matches them to user accounts and lets you target/exclude.

For e-commerce:

• Upload past customer list. Use as exclusion in acquisition campaigns.
• Upload top-LTV customer list. Use as bid modifier (+30% to spend more on similar users).
• Upload churned customer list. Target with win-back messaging.

Customer Match audiences refresh automatically if you connect them via API (Klaviyo, Shopify).

RLSA mistakes to avoid

• Audiences too small to use. Need 1,000+ users per audience for Search.
• Setting bid modifiers without data. Just adding +50% without checking actual performance lift.
• Forgetting to exclude purchasers from acquisition. Wasting acquisition budget on existing customers.
• Using same audience across all campaigns. Different campaigns need different bid logic.
• Audience overlap unmanaged. A user might be in 3 audiences with conflicting bid modifiers — Google picks the highest.

RLSA for shopping campaigns

Standard Shopping campaigns can use audiences too. But:

• PMax handles it automatically; you can't manually set RLSA modifiers in PMax.
• Standard Shopping (when still relevant) supports audience bid adjustments.

For PMax: add audiences as "audience signals" in asset groups. They guide the algorithm but don't lock targeting.

A 30-day RLSA rollout

If your account isn't using RLSA:

• Week 1: Set up audiences (visitors, product viewers, cart abandoners, past purchasers).
• Week 2: Add audiences to all search campaigns in Observation mode.
• Week 3: Pull 7-day performance data. See which audiences convert above baseline.
• Week 4: Add bid modifiers (or Smart Bidding learns implicitly). Create one dedicated RLSA campaign with broader keywords for past visitors.

Most accounts see 10-25% search conversion lift within 60 days of implementing RLSA properly.

Performance benchmarks

For a healthy account with RLSA:

• Past visitor conversion rate: 2-4x baseline.
• RLSA-targeted campaigns ROAS: 30-100% higher than cold search campaigns.
• Past purchaser exclusion: saves 5-15% of acquisition budget.
• Cart abandoner search bid: justifies 50-100% bid uplift profitably.

What "good" looks like

A clean RLSA setup:

• All search campaigns have audiences in Observation mode.
• Past purchasers excluded from acquisition campaigns.
• One dedicated RLSA-targeting campaign for broader keywords.
• Customer Match lists from CRM, refreshed weekly.
• Clear bid modifier logic documented per audience.

RLSA isn't fancy. It's hygiene. The accounts that treat it as standard practice quietly outperform accounts that don't, year after year.