Auto vs Broad vs Exact: How Much Should You Spend by Match Type on Amazon PPC?

“What percentage of my budget should go to auto, broad, and exact?” It’s one of the most common questions we hear from Amazon sellers — and one of the most misunderstood. Because the honest answer isn’t a magic ratio. It’s “it depends on where you are in your product lifecycle, how much data you have, and what you’re trying to accomplish.”

But that’s not a satisfying answer, so let’s do better. Let’s talk about how to think about budget allocation across match types, what the data actually tells us about where most sellers should be spending, and the common mistakes that cause sellers to either waste money on discovery they don’t need or starve themselves of the new keywords that could transform their account.

If you’ve ever felt like you’re throwing money into auto campaigns with nothing to show for it — or like your exact match campaigns are capped out and you can’t find growth — this one’s for you.

Understanding What Each Match Type Actually Does

Before we talk about how much to spend, let’s make sure we’re aligned on what each match type is for. This matters more than you think, because budget allocation should follow strategy, not the other way around.

Auto campaigns are Amazon’s discovery engine. You’re handing Amazon the keys and saying, “You figure out what search terms are relevant to my product.” Amazon uses your listing content, category, and backend keywords to match you to searches. Auto campaigns serve four targeting groups: close match, loose match, substitutes, and complements.

• Best for: Finding new search terms you didn’t know about, early-stage products with no keyword data, defensive targeting on your own listings
• Limitations: Less control, often higher ACoS, can spend on irrelevant terms

Broad match gives you more control than auto but still casts a wide net. Your keyword “stainless steel water bottle” might match “insulated metal water bottle for hiking” — Amazon adds words, reorders them, and considers synonyms.

• Best for: Expanding on keyword themes you’ve identified, finding long-tail variations, bridging the gap between auto discovery and exact match precision
• Limitations: Can still match to loosely related terms, requires active negative keyword management

Exact match is your precision tool. The search term must closely match your keyword (Amazon does allow close variants and plurals). These campaigns typically have the best ACoS because you’re only showing up for terms you’ve intentionally chosen.

• Best for: Scaling proven winners, controlling costs, maximizing efficiency on high-converting terms
• Limitations: No discovery — you only get what you put in, can plateau if not fed by broader campaigns

The Match Type Lifecycle: A Framework for Allocation

Here’s the framework that actually works: think of your match type allocation as a sliding scale that shifts as your product matures.

Phase 1: Launch (Weeks 1-8)

Recommended allocation: 50-60% Auto / 20-30% Broad / 10-20% Exact

When you launch a new product, you don’t know what you don’t know. You might have done keyword research and identified 50 target keywords, but Amazon’s search behavior is messy and unpredictable. Shoppers use terms you’d never think of. Auto campaigns are your most valuable asset during this phase because they’re the fastest way to gather real search term data.

At the same time, you should have a broad campaign running on your best keyword themes and a small exact campaign with your highest-confidence keywords (branded terms, obvious head terms). But the bulk of your spend should be going toward discovery.

The goal in this phase isn’t efficiency — it’s data. You’re buying information. A 50% ACoS on your auto campaign isn’t a failure if it’s surfacing 20 new converting search terms you can promote to exact match.

Phase 2: Growth (Months 2-6)

Recommended allocation: 25-35% Auto / 25-35% Broad / 30-40% Exact

By now, you should have harvested a meaningful number of search terms from your auto and broad campaigns. Your exact match campaign should be growing as you add proven winners. The balance starts to shift.

This is where the search term funnel becomes critical:

1. Pull your search term report weekly (or at least biweekly)
2. Identify search terms with 2+ conversions and an acceptable ACoS
3. Add those as exact match keywords
4. Add those same terms as negative exact in your auto and broad campaigns

Your auto campaign budget doesn’t need to drop to zero — there are always new terms to discover, especially as Amazon’s catalog and search behavior evolve. But it should represent a smaller share of total spend as your exact match campaign takes over the heavy lifting.

Phase 3: Optimization / Maturity (Month 6+)

Recommended allocation: 15-20% Auto / 15-25% Broad / 50-65% Exact

For a mature product with strong keyword data, the majority of your spend should be on exact match. These are your known converters. You’ve tested them, you have statistical significance on their performance, and you can bid with confidence.

Auto and broad campaigns shift to a maintenance role — still running, still discovering, but at a lower budget. Think of them as your “always-on” research engine, not your primary sales driver.

Important caveat: These percentages aren’t rules — they’re guidelines. If your auto campaign is still finding gold at month 8, don’t cut it just because a framework says to. Follow the data.

The Data-Driven Approach: Let Performance Guide Allocation

Here’s where it gets practical. Instead of following a fixed ratio, use these metrics to decide where your next dollar should go:

ACoS by match type. If your exact match campaigns are running at 15% ACoS and your auto campaigns are at 45% ACoS, the math is straightforward — more budget to exact, less to auto. But if your auto campaigns are at 25% ACoS and surfacing new terms monthly? Keep feeding them.

New-to-brand keyword velocity. How many new converting search terms is each campaign type generating per week? If auto is still producing 5+ new converting terms weekly, it’s earning its budget. If it hasn’t surfaced a new winner in three weeks, it might be time to trim.

Impression share and budget caps. If your exact match campaigns are hitting their daily budget by 2 PM, you’re leaving money on the table on your best-performing targeting. Reallocate from lower-performing match types before increasing total spend.

Conversion rate by match type. Exact match typically converts at 2-3x the rate of auto. But if your broad match campaigns are converting at near-exact rates, that tells you there’s opportunity to scale broad — and likely promote more of those terms to exact.

Here’s a simple exercise: pull your last 30 days of data, break it down by match type, and ask yourself:

• Which match type has the best ACoS?
• Which match type is generating the most new converting search terms?
• Which match type is budget-constrained?
• Which match type is spending without converting?

The answers will tell you exactly where to shift your allocation.

Common Mistakes in Match Type Budget Allocation

Mistake 1: Running Auto Campaigns Forever at Launch Budgets

We see this constantly. A seller launches with a $50/day auto campaign, and 18 months later it’s still running at $50/day even though it hasn’t surfaced a new converting search term in months. Meanwhile, their exact match campaigns are capped at $30/day and hitting budget by noon.

The fix: Review auto campaign discovery on a monthly basis. If the well is dry, reduce the budget and reallocate to exact.

Mistake 2: Skipping Broad Match Entirely

Some sellers go straight from auto to exact and skip broad altogether. This leaves a gap — there are long-tail variations and keyword combinations that auto might not surface but broad will. Broad match acts as a bridge, and skipping it means you’re leaving keywords (and sales) undiscovered.

Mistake 3: Not Using Negative Keywords (The Cardinal Sin)

If you’re running auto, broad, AND exact campaigns for the same product without negative keywords, your campaigns are competing against each other. The same search term triggers all three match types, you’re bidding against yourself in the auction, and your data is polluted.

The rule: When you promote a search term to exact match, add it as a negative exact in your auto and broad campaigns. No exceptions. This is the single most important maintenance task in Amazon PPC.

Mistake 4: Treating All Products the Same

Your hero SKU with 500 reviews and a 20% conversion rate doesn’t need the same match type allocation as your new launch with 5 reviews. Higher-converting products can afford to be more aggressive with discovery (auto and broad) because even “expensive” clicks still convert at acceptable rates. Lower-converting products need to focus spend on exact match where intent is highest.

Mistake 5: Chasing a “Perfect” Ratio

There’s no universal 20/30/50 split that works for every product, every category, every competitive landscape. Sellers who obsess over matching some guru’s recommended ratio end up making allocation decisions based on theory instead of their actual data.

The fix: Start with a reasonable baseline, then let your search term reports and performance metrics guide adjustments every 2-4 weeks.

Advanced Strategies: Going Beyond the Basics

Once you’ve nailed the fundamentals, here are some more advanced tactics:

Dayparting by match type. If your exact match campaigns perform best during business hours (when purchase intent is highest) and your auto campaigns discover more efficiently during off-peak hours (when CPCs are lower), consider adjusting budgets or using dayparting rules to capitalize on these patterns.

Separate auto campaign targeting groups. Amazon’s auto campaigns have four targeting groups (close match, loose match, substitutes, complements). You can’t separate them into different campaigns natively, but you can use negative targeting aggressively to shape which groups spend. Or create multiple auto campaigns — one with higher bids on close match, another focused on substitutes for competitive conquesting.

Portfolio-level budget management. Amazon’s portfolio feature lets you set an overarching budget cap across multiple campaigns. Use this to control total spend by product while still letting individual match type campaigns flex within that cap based on performance.

Seasonal rebalancing. During peak seasons (Q4, Prime Day), discovery becomes less important — you should already know your winning keywords. Shift budget heavily toward exact match to maximize efficiency during high-traffic periods. Post-peak, swing back toward discovery as shopping behavior shifts.

Conclusion / Key Takeaways

Budget allocation across match types isn’t a set-it-and-forget-it decision. It’s a dynamic strategy that should evolve with your product lifecycle and respond to real performance data. Here’s what to remember:

• Early stage: Heavy on auto (50-60%) for discovery. You’re buying data, not just sales.
• Growth stage: Balanced across all three match types (roughly equal thirds) as you build your exact match keyword base.
• Mature stage: Majority on exact (50-65%) where your proven winners live. Auto and broad shift to maintenance mode.
• Always: Run the search term funnel. Harvest winners, negate them in source campaigns, repeat weekly.
• Never: Set a ratio and ignore it. Review match type performance every 2-4 weeks and reallocate based on ACoS, conversion rate, and discovery velocity.
• The cardinal rule: Use negative keywords to prevent self-competition across match types. This alone can transform your account efficiency.

The sellers who win at Amazon PPC aren’t the ones who found the “perfect” ratio. They’re the ones who built a system for continuously moving dollars from where they learn to where they earn — and they do it consistently, week after week.

Start where you are. Follow the data. Adjust. Repeat.

This article is based on Episode 89 of That Amazon Ads Podcast. Subscribe for weekly Amazon PPC strategies.