Amazon’s Rise as a Search Engine

There was a time when “search engine” almost automatically meant Google. But today, when consumers are looking to buy products, their search often begins on platforms like Amazon.

While Google still dominates traditional search marketing, 57% of US consumers now begin their online shopping searches on Amazon. For brands, that means search engine marketing (SEM) can’t just mean Google Ads anymore. Where and how you allocate your advertising budget needs to evolve — unless you want to miss out on a massive pool of high-intent customers.

Amazon’s Rise as a Search Engine

Amazon has evolved beyond being an online retailer into a fully-fledged product discovery engine, complete with robust targeting tools, search rankings, sponsored placements, and closed-loop attribution — all backed by data from billions of customer interactions.

Think about your own shopping habits: when you know what kind of product you want, where do you start? When you’re starting research on a product, where do you start?  Google searches tend to span the entire funnel — from information gathering, to product comparisons, to transactions. Amazon searches, on the other hand, are predominantly transactional. Because Amazon users are typically comparing products or searching for a specific brand, their intent is much closer to purchase — making Amazon a powerful, lower-funnel search engine.

SEM vs. Amazon: It’s Not Either/Or

The rise of Amazon doesn’t mean traditional SEM is dead. They serve different, complementary roles in the funnel. Understanding when and why to invest in each is key to maximizing ROI.

The Strengths of Google SEM 

Google SEM plays a critical role in capturing users across the funnel, particularly during discovery and consideration stages. Its key strengths include:

• Broad Reach: Brands can connect with users throughout their entire purchase journey, from initial research to the final sale.
• Precise Audience Targeting: Brands can reach high-intent and niche audiences by utilizing demographic, interest-based, and custom audience tools.
• Content Distribution: Traffic can be driven to educational content such as blogs and guides, effectively nurturing prospects as they consider their options.
• Brand Visibility and Protection: Brands can secure top positions for branded queries and defend against competitor bidding on their brand terms.
• Lead Generation: Google can help brands with longer consideration cycles (such as automotive, finance, and complex consumer goods) capture qualified leads.

The Strengths of Amazon 

Amazon is highly effective at capturing high-intent shoppers and converting demand at the point of purchase. Its core strengths include:

• High Purchase Intent: Shoppers on Amazon are often ready to buy, making it an ideal platform for immediate sales.
• Product-Centric Search Behavior: Listings appear exactly when users are searching for specific products or categories.
• Seamless Path to Purchase: Ads live within the buying environment, minimizing friction between ad engagement and checkout.
• Closed-Loop Attribution with First-Party Purchase Data: As both the ad platform and point of sale, Amazon offers a closed-loop system that directly links ad views to browsing, cart activity, and purchases — all within one ecosystem.
• Boosting Organic Rankings: Paid campaigns increase sales velocity, which can improve organic placement in Amazon search results.

Rather than choosing between platforms, the most effective strategy is to integrate both based on where the customer is in the journey.

 

Funnel Stage	Channel / Ad Type	Why
Awareness & Discovery	SEM: Non-branded search terms, broad match keywords, upper-funnel queries Amazon: Sponsored Brand Ads, non-branded search terms Both Platforms: Educational content ads, Category-level targeting	Capture broad intent and educate early-stage shoppers.
Consideration	SEM: Branded search terms, competitor keywords, product-specific and comparison search terms   Amazon: Sponsored Brand + Sponsored Display Ads, product comparison pages   Both Platforms: Retargeting ads for product education, Review-focused content	Drive mid-funnel engagement through reviews, comparisons, and educational content
Decision & Purchase	SEM: Retargeting ads, specific product searches, “ready to buy” keywords, local inventory ads   Amazon: Sponsored Product Ads, Product Display Ads, DSP retargeting Both Platforms: Retargeting for cart abandoners, Promotional offer ads	Reach ready-to-buy shoppers and drive conversion through high-intent targeting

 

Rethinking Attribution and Strategy

While Google offers a sophisticated tracking and attribution system, Amazon’s ecosystem remains mostly siloed from traditional SEM platforms. This fragmentation creates blind spots when trying to measure the full impact of marketing efforts across channels. To build a more complete view of performance:

• Leverage clean rooms: Clean rooms — like Amazon Marketing Cloud (AMC) — let brands analyze data from multiple sources in a privacy-safe environment. When paired with data stored in S3 buckets, they offer a more complete view of performance across platforms, all without compromising user privacy.
• Focus on incremental lift: Instead of relying only on direct attribution within individual platforms, track broader changes in sales, brand awareness, and customer engagement when campaigns run across both SEM and Amazon.
• Implement Marketing Mix Modeling (MMM): MMM offers a high-level perspective on how all marketing investments — not just paid search — contribute to overall business outcomes over time.
• Conduct lift studies: Use geo-based lift tests on Google to measure upper-funnel impact, and run product level lift studies on Amazon to assess the incremental value of retail media. Together, they help quantify how each platform contributes across the funnel.
• Standardize taxonomy and tracking: Consistent campaign naming, tagging, and audience structures across Google and Amazon simplify cross-channel measurement and ensure cleaner reporting.

 

Rethinking Budget Allocation 

It’s not about choosing between Google or Amazon — it’s about optimizing your budget across both to maximize return. The most effective strategy uses marginal budget allocation: investing each additional dollar where it delivers the highest return. Business objectives and product category will help guide where to lean in, but in most cases, success comes from balancing both platforms — not picking just one.

Consider Business Objectives

• If the goal is building awareness, Google SEM is a powerful tool for reaching new audiences through non-branded, broad-match, and category-level keywords. These campaigns help introduce your brand to shoppers who haven’t yet formed preferences. Amazon’s brand-building tools — such as Sponsored Brands and Stores — can complement this by reinforcing awareness within the marketplace environment.
• If the primary goal is direct conversions, Amazon Ads — particularly Sponsored Products and Display — are often highly effective, especially for products with strong marketplace traction. Simultaneously, Google Ads (like branded search and remarketing) can efficiently capture high-intent users ready to convert.
• For lead generation or subscription-based brand, Google excels at top-of-funnel education and content-driven lead capture. After acquisition (on either platform), Amazon features like Subscribe & Save and auto-reorder can help increase customer lifetime value (LTV) by driving repeat purchases.

Consider Product Category

• High-research categories like electronics or appliances benefit from strategic budget allocation across both Google and Amazon. Google is often effective during the early stages of the journey — when consumers are exploring options, reading reviews, and gathering information. As purchase intent increases, Amazon often plays a critical role in product comparison and final conversion.

• Routine purchases like personal care or household goods, see strong return on investment (ROI) on Amazon due to built-in purchase behaviors and ease of reordering. However, Google is still valuable for reaching new audiences or driving competitive visibility. Your investment split should be guided by the comparative cost-per-acquisition (CPA) and LTV generated by each platform.
• New-to-Market products require both demand creation and conversion. Broad and mid-funnel Google campaigns are effective for educating shoppers and generating interest, while Amazon can help capture that intent as it grows. Monitor search trends across both platforms to guide budget allocation and ensure your brand shows up where potential customers are actively searching.

 

WITHIN’s Tips:

• Keep overall profitability top of mind when allocating budgets across platforms. Factor in total costs — including Amazon’s selling fees — to ensure your ad dollars are not only driving sales, but also contributing positively to your bottom line after all fees are accounted for.

• Adjust platform investment based on seasonal moments — leaning into awareness and conversion where each platform performs best. For example, prioritize SEM around Black Friday for early discovery, and ramp up Amazon spend during Prime Day to capture high-intent shoppers.
• Watch how shifts in upper-funnel media — especially on Meta or Google — can impact performance on Amazon. Building demand through broad-reach channels often drives incremental lift across lower-funnel platforms, including retail media.
• Allocate 15–20% of budget toward protecting your brand terms on both platforms, with the remainder focused on broader competitive and category terms.

 

What This Means for Marketers

As consumer behavior evolves, marketers must build SEM strategies that reflect how — and where — people actually shop. Platforms like TikTok and AI-driven tools are capturing more search volume, while retail media networks such as Walmart, Target, and Chewy are capturing greater purchase intent. This isn’t about abandoning Google or replacing SEM with retail media — it’s about integrating platforms strategically to reach customers at every stage of their decision-making process.

Agencies like WITHIN, with expertise in both traditional SEM and Amazon Ads, can help brands develop integrated strategies that maximize awareness, conversion, and long-term growth.