Share of Voice (SOV) is the percentage of total advertising visibility your brand captures in a product category compared to your competitors. In retail media, it’s one of the most actionable indicators of whether your brand is winning or losing on the digital shelf.
ROAS tells you how efficiently your ads are converting. It doesn’t tell you how visible you are relative to the brands competing for the same shopper. SOV fills that gap. Calculated as your brand’s ad impressions (or spend, clicks, or sales) divided by the total in the market, multiplied by 100, it gives you a clear read on competitive standing, not just campaign efficiency.
In this guide, you’ll find a breakdown of what SOV is, how to calculate it across Amazon, Walmart, and Instacart, how to use it to prioritize ad spend, defend against competitor conquesting, and build organic share over time, with real examples from brands using Pacvue’s SOV tracking today.
What is Share of Voice in Retail Media?
Share of Voice measures the percentage of total advertising visibility your brand captures in a product category compared to all competing brands over a specific time period. In retail media specifically, SOV reflects how visible your brand is within sponsored search results on retailer platforms.
Whether you’re selling on Amazon, Walmart, Instacart, or across multiple retailers, SOV tells you three things:
- How much paid real estate you own. What percentage of ads in your category belong to your brand, across display, sponsored products, and search placements.
- Where you stand against competitors. A 30% SOV on Amazon means 30% of all advertising impressions in your category belong to you. That context is something ROAS alone can’t give you.
- Where to put your budget. A lower SOV on a high-priority keyword or retailer is a direct signal that investment is needed.
What’s the Difference between Share of Voice and Share of Shelf?
The key difference comes down to traffic source: paid vs. organic.
Share of Voice measures visibility only through paid advertising. It reflects your investment in sponsored products, brands, and video ads across retailer platforms.
Share of Shelf (SOS) captures both paid and organic visibility. It reflects not just your ad spend, but how well your products rank organically as well — your total share of search.
Most brands track both. SOV tells you how effectively you’re using paid media. SOS shows you whether that paid investment is translating into organic rankings over time.
How to Calculate Share of Voice in Retail Media
Think of SOV as a pie chart showing how much of the advertising pie your brand controls in a given category.
The formula:
SOV = (Your Brand’s Ad Impressions ÷ Total Market Ad Impressions) × 100
Example: Your ads received 1,000 impressions over 30 days. Total impressions across all brands in your category: 10,000.
SOV = (1,000 ÷ 10,000) × 100 = 10%
The more visible you are to shoppers, i.e., the higher your Amazon ranking and share of search, the more likely you are to dominate the category.
Why Share of Voice Is a Suite of Metrics, Not a Single Number
SOV isn’t one number. It’s a framework you can apply at multiple levels: impressions, clicks, spend, sales, paid, organic, by keyword, by product, by retailer, or by campaign. That flexibility is what makes it useful.
You can use it for a high-level view of your brand’s overall competitive position, or drill into individual SKUs and specific search terms. You can compare paid SOV to organic SOV to understand whether your ad spend is actually building shelf presence over time.
Calculating this manually and consistently isn’t realistic at scale. That’s why Pacvue builds SOV tracking directly into the platform: the value comes from continuously monitoring it, not from pulling a number once a quarter.
How Tuft & Needle used Pacvue’s SOV tracking to diagnose a spike in their CPC
When Tuft & Needle saw a sudden increase in CPC, they used Pacvue’s SOV tracking to investigate. The data showed a competitor had started targeting their branded keywords and was running a 25% off promotion to pull customers away. Without SOV visibility, that would have looked like a random cost increase. With it, they had a clear picture of what was happening and why.
How to Use Share of Voice to Prioritize Ad Spend
SOV makes it possible to see not just how your campaigns are performing, but where you’re underrepresented relative to competitors. That gap is where budget decisions should start.
If SOV is low on high-priority keywords, that’s a visibility problem. If SOV is strong but sales haven’t moved, that’s a conversion problem. The two require different responses, and SOV is what helps you tell them apart.
How to Use Share of Voice with Pacvue’s Bid Explorer
The previous example focused on impressions, but it’s important to note that your ads’ Share of Voice isn’t just a single metric—it’s a suite of metrics that reflect various aspects of competitive performance and visibility. This versatility is what makes SOV so valuable. One of the key strengths is that the SOV for both you and your competitors can be calculated in multiple ways. The concept can be applied to impressions, clicks, traffic, sales, and more. With SOV, you can gain a high-level overview of your brand’s performance or drill down for detailed analysis of individual products or campaigns. You can assess overall search terms, then drill down into paid vs. organic SOV, analyze keywords, and explore consumer demographics.
Hopefully, you’re now getting to grips with just how valuable and versatile SOV is, and how tedious and time-consuming it would be to calculate it manually on an ongoing basis. That’s why we’ve built Share of Voice analysis into our Pacvue platform, because the real value in Share of Voice comes from tracking this metric on an ongoing basis. Let’s look at the kind of insights you can get when you automate SOV tracking and how it can inform your decision-making.
How Share of Voice can protect your brand visibility
Pacvue’s Bid Explorer uses historical performance data to recommend bid levels based on current CPC trends and competitor activity. Paired with SOV tracking, it creates a feedback loop:
- Identify keywords where your SOV is below target.
- Use Bid Explorer to forecast performance at different bid levels.
- Increase bids, monitor SOV weekly, and confirm whether share gains translate to sales.
- Track organic SOV alongside paid to capture halo effects as they develop.
Share of Voice Across Retailers
Competitive dynamics vary significantly by platform. The same category can look completely different on Amazon versus Walmart, and that gap is an opportunity if you’re paying attention.
Amazon
Amazon’s sponsored search is highly competitive and fragmented. In a consumer electronics analysis using Pacvue, 84 brands were actively competing for the top 10 keywords in the category. Not one of them held more than 10% of paid SOV. In a fragmented market, small share gains matter, and monitoring SOV closely is the only way to spot them.
Walmart
The same keyword analysis on Walmart showed a completely different picture: two brands actively participating, with one holding more than 90% of paid SOV. The competitive window on Walmart can close quickly once other brands recognize the opportunity. Brands that move early and track SOV consistently are the ones positioned to own it.
Instacart
Instacart presents a different challenge. It doesn’t offer unblinded category insights, which makes it harder to directly identify top competitors. Pacvue provides granular SOV tracking and keyword trend data down to the SKU level, beyond what Instacart’s native UI offers, including placement locks that let you consistently hold specific ad positions on high-value keywords.
How Paid Share of Voice Creates an Organic Halo Effect
Retailer search algorithms are driven by sales volume. The more your product sells, the better it ranks organically. That means a well-executed paid SOV strategy can lift organic rankings over time, compounding the return on your ad spend without requiring you to continuously increase it.
Tracking both paid and organic SOV together is the clearest way to see whether your campaigns are building lasting shelf presence or just buying temporary visibility.
A global beauty brand increased organic share of search by 36% on Amazon by targeting SOV gaps for the keyword “mascara” across multiple sub-brands. Rather than raising total spend, they increased bids by 60% when products weren’t appearing prominently and made ASIN-specific adjustments to surface high-volume and underperforming items. The result: a 36% increase in organic share of search for the targeted sub-brand and a 24% lift in SOV across the broader portfolio.
4 Best Practices for Improving Share of Voice in Retail Media
1. Track SOV continuously, not periodically. The competitive landscape shifts constantly. A competitor can enter a keyword overnight and erode your position within days. Automated SOV dashboards and alerts let you respond in real time rather than discovering problems weeks later.
2. Monitor competitors’ keywords, not just your own. Knowing which keywords competitors are investing in tells you where they see the most opportunity. Use that intelligence to defend your position on branded terms and identify openings on category terms where you’re underrepresented.
3. Focus investment on your highest-impact products. Not every SKU needs equal coverage. Concentrate your SOV strategy on the products driving the most impressions, clicks, and sales. A concentrated approach builds a stronger presence on the products that matter most, rather than spreading the budget thin across the entire catalog. Brands looking to sharpen this approach can find category-specific playbooks in Winning the Digital Shelf.
4. Make sure your PDPs can convert the traffic you win. Gaining SOV creates visibility. It only generates revenue if the product page can close the sale. High-quality images, detailed descriptions, relevant keywords, and strong reviews are what turn SOV gains into actual market share growth.
Share of Voice Is How You Know You’re Winning
Share of Voice gives you a competitive lens that ROAS alone can’t provide. It tells you where you stand, where you’re losing ground, and where there’s room to grow — across every retailer, keyword, and campaign you’re running.
Connect with our commerce experts to see how Pacvue’s SOV tracking can sharpen your retail media strategy.
