March 18, 2025
17:30 minutes
Alasdair Hamilton
February 11, 2026
23 minutes

Proven revenue driver – Product recommendation engines contribute a disproportionate share of retail sales. For example, roughly 7% of recommendation clicks can drive about 26% of online revenue, and Amazon attributes around 35% of its e-commerce sales to its AI-powered recommendation system.
Boosts key metrics – AI personalisation via product recommendations significantly improves performance metrics. Personalised suggestions can lift conversion rates (shoppers who click recommendations may be 4.5× more likely to purchase), increase basket size and average order value (up to 31% more items per order in some cases), and extend customer lifetime value through better loyalty and repeat purchases.
ROI is measurable – Retail personalisation ROI can be clearly calculated by comparing the incremental sales and profit from recommendations against the system’s costs. Many retailers see outsized returns on these engines – in some cases over 2000% ROI (every $1 spent on the technology returns $20 in revenue).
Best practices matter – To maximise ROI, companies must deploy recommendation engines strategically: ensure highly relevant suggestions, test and optimise continuously, and integrate recommendations across channels (web, email, mobile, in-store) for a true omnichannel retail experience.
Product recommendation engines have become a staple of modern omnichannel retail tech. From e-commerce sites to physical stores, these AI-driven personalisation tools present tailored product suggestions (“You might also like…”, “Frequently bought together”) that enhance the customer experience and boost sales. Powered by algorithms analysing customer data – browsing history, past purchases, preferences – a recommendation engine acts like a digital personal shopper, predicting what each customer is most likely to buy next. The result is a more engaging, personalised shopping journey that drives incremental revenue.
Major retail success stories underscore the impact of getting recommendations right. Amazon’s recommendation engine, for instance, is estimated to drive roughly 35% of the company’s online sales. More broadly, although only a small portion of site visitors (around 7%) click on recommended products, those interactions often generate about 26% of total online revenue. In other words, a well-tuned recommendation system punches far above its weight in converting shoppers and increasing sales.
Given these impressive figures, retail executives naturally ask: Is our investment in product recommendation technology paying off? In other words, what is the return on investment for our personalisation efforts? Measuring ROI on product recommendations is crucial to understanding their business value and justifying ongoing investment. In the following sections, we outline how to evaluate product recommendation engines by ROI – from defining ROI in this context and tracking key metrics (conversion rates, basket size, customer lifetime value, etc.), to methods for attributing results and best practices for maximising returns. This provides a clear framework for decision-makers to assess the value generated by AI personalisation tools and ensure they contribute meaningfully to the bottom line.
Product recommendations in retail are the tailored product suggestions offered to shoppers based on their likely interests and behavior. These can appear in many forms – on e-commerce sites (for example, a “Recommended for you” carousel or “Customers who bought this also bought…” prompts) and even in physical stores (such as a sales associate with a tablet suggesting complementary items). The power of these recommendations comes from personalisation. Instead of showing the same best-sellers to everyone, modern product recommendation engines leverage customer data and AI to present items each individual shopper is likely to want. Essentially, it’s like having a knowledgeable sales assistant who knows each customer’s tastes, but automated and scalable across digital and physical channels.
In practice, a recommendation engine analyses patterns (e.g. viewing or purchase history, items frequently bought together, similar customer profiles) to predict products that might interest a specific shopper. For the customer, this means a smoother, more personalised shopping experience – they discover relevant products with less effort. For the retailer, it means higher engagement and a greater chance to increase sales through relevant cross-sells and upsells. In an age where consumers expect seamless, omnichannel retail experiences, these engines play a key role in delivering consistent personalisation across web, mobile, email, and store touchpoints.
Investing in a product recommendation engine isn’t just a tech upgrade – it directly impacts critical business outcomes. Effective recommendations improve customer experience and drive incremental sales, which together boost ROI. Here are a few key ways these engines add value:
In short, product recommendation engines directly influence the key levers of retail profitability: they convert more shoppers, increase spend per transaction, and keep customers coming back. All of these effects feed into a stronger return on investment for the technology.
Return on Investment (ROI) is a straightforward formula: it measures the profitability of an investment relative to its cost. In formula terms:
ROI = (Net Profit from the Investment ÷ Cost of the Investment) ×100%
For a product recommendation engine initiative, the “investment” includes all costs of the system – software subscription or license fees, integration and development expenses, maintenance and support costs, and any related operational spending. The “return” is the additional profit generated thanks to the recommendation engine. Typically, this return materialises as incremental sales that would not have occurred without those personalised recommendations.
The key to calculating ROI in this context is isolating the incremental lift provided by the recommendation engine. In other words, how much extra revenue (and profit) is the engine responsible for, beyond your baseline sales without recommendations? This often requires analysis and experimentation to tease out. Retailers might run controlled trials (showing recommendations to some customers but not others) or use analytics attribution models to estimate how many sales were driven by the recommendations.
For example, suppose you spend $10,000 on a recommendation engine in a given period, and you determine that the personalised recommendations generated an additional $50,000 in net profit (after accounting for the cost of goods, etc.) that you would not have had otherwise. Using the ROI formula, that would be:
ROI = ($50,000 ÷ $10,000) × 100% = 500%
In this simplified scenario, every $1 invested in the recommendation engine returned $5 in profit – an excellent result. Of course, in reality, measuring this “extra” profit precisely can be complex; it might involve multiple data points and assumptions. You’ll want to look at a combination of metrics (detailed in the next section) and possibly conduct A/B tests to confidently attribute sales uplift to the recommendation engine. But the fundamental idea remains: if the value generated by the engine far exceeds its cost, the ROI will be high, indicating a worthwhile investment.
Next, we’ll delve into the specific metrics that help capture this value.
To evaluate a product recommendation engine’s ROI, you should monitor a core set of metrics that reflect how the engine is influencing shopper behavior and revenue. The most important metrics include conversion rate, average order value, basket size, customer lifetime value, and the share of revenue attributable to recommendations. Let’s look at each of these:
Conversion rate is the percentage of visitors (or sessions) that result in a purchase. A strong recommendation engine will lift conversion rates by turning more browsers into buyers. One way to gauge this is to compare the conversion rate of customers who interact with recommendations to those who do not. Often, the difference is dramatic. For instance, if your site’s baseline conversion rate is around 2%, shoppers who click on at least one recommended product might convert at, say, 4–5%. In one analysis, sessions with no recommendation clicks had roughly a 1% conversion rate, whereas even a single recommendation click raised conversion likelihood to nearly 4%, with further interactions boosting it higher. This kind of jump illustrates that relevant recommendations can directly translate into more completed purchases. To measure this effect rigorously, you can run an A/B test (show recommendations to a test group while hiding them for a control group) and see if the test group’s conversion rate is significantly higher. A clear uptick in conversion attributable to recommendations means your engine is driving genuine incremental sales – a key component of ROI.
Average Order Value is the average amount a customer spends in a single purchase. Recommendation engines often increase AOV by encouraging customers to add more to their cart or choose higher-priced items. If you notice that after implementing personalised recommendations your AOV has gone up, that’s a strong sign of success. For example, a customer who originally planned to buy a $100 item might, after seeing a recommended add-on, end up spending $130 in that session – raising the value of that order. Across many transactions, these upsells and cross-sells significantly boost revenue. Many retailers observe that sessions with recommendation engagement have higher AOV than those without. From an ROI perspective, a higher AOV means you’re generating more revenue per transaction, which improves the return on the fixed costs of running your store and the recommendation system. In summary, if recommendations are lifting AOV, they’re directly contributing to ROI growth by extracting more value from each customer visit.
Closely related to AOV is the basket size – the number of items each customer buys per order. An effective recommendation engine often leads shoppers to add extra items to their cart, increasing the average basket size. Even if those additional items are low or medium-priced, the cumulative effect can be substantial. For example, after introducing personalised product suggestions, you might see your average items per order rise from 1.2 to 1.5. That change indicates customers are indeed picking up that “you might also like” second item, or adding an accessory recommended alongside a main product. One retailer reported a 31% increase in items per order after deploying an AI-driven recommendation engine, clearly demonstrating how suggestions can encourage multi-item purchases. Larger basket sizes mean higher total sales for the same number of orders, which again boosts the ROI of the recommendation initiative. It shows the engine is not just converting customers, but also increasing how much each customer buys.
Customer Lifetime Value represents the total revenue you expect to earn from a customer over the entire relationship. Improvements in CLV come from increasing customer loyalty, frequency of purchases, and reducing churn. Product recommendation engines can positively impact CLV by improving the shopping experience and satisfaction, leading customers to shop more often and for a longer period of time. Signs of this influence include higher repeat purchase rates and customer retention after personalisation is introduced. For instance, if you track a cohort of new customers and find those who engaged with recommendations on their first visit returned and bought again at a much higher rate, that suggests the recommendations are fostering loyalty. As noted earlier, first-time shoppers who click a recommendation were nearly 2× as likely to return in future. Similarly, you might see the average time between purchases shorten (customers come back sooner) or an increase in the percentage of customers making multiple purchases in a year. All these indicate a rising CLV. From an ROI standpoint, higher CLV is gold – it means you get more revenue from each customer acquired, which dramatically improves profit margins. A recommendation engine that helps boost retention and lifetime value is delivering long-term returns that might dwarf the immediate short-term sales uptick.
One of the most direct measures of a recommendation engine’s impact is the amount of sales directly tied to it. Many analytics tools can track when a purchase occurred after a customer clicked or viewed a recommended item. By looking at these reports, you can quantify what portion of your revenue is influenced by recommendations. It’s not uncommon for retailers to find that 10% to 30% of their e-commerce revenue is coming from products that were surfaced by the recommendation engine. For example, you might discover that in the last quarter, 15% of all online sales involved a customer interacting with a recommended product at some point in their journey. That percentage of revenue can be considered incremental output of the engine (assuming those sales would likely not have happened without the recommendation prompt). This metric is extremely useful for ROI calculations: if a significant share of your revenue is recommendation-driven, and you know what you’re spending on the engine, you can calculate a very tangible ROI. The higher the attributed revenue relative to cost, the higher the ROI. Just ensure to interpret attributed revenue carefully – ideally it should reflect truly incremental sales, as opposed to sales that might have occurred anyway. (Techniques like holdout tests help confirm how much of that attributed revenue is incremental.)
By monitoring these key metrics, you build a quantitative picture of how the recommendation engine is performing. If the trends are positive – higher conversion, bigger baskets, more repeat business, and a healthy chunk of sales coming from recommendations – then you’re likely seeing a strong ROI. If not, these metrics will also signal where improvements are needed.
Tracking metrics is only half the battle. The other half is using that information to measure ROI accurately and boost it over time. Here are some practical methods and considerations for evaluating and improving your product recommendation engine’s ROI:
By applying these methods, you not only measure the ROI more accurately but also actively enhance it. A recommendation engine’s performance can change as your product catalog, customer base, or market trends change, so iterative testing and optimisation ensure you sustain high returns in the long run.
Finally, to get the most out of your investment, consider these best practices. They are drawn from what successful retailers do to ensure their product recommendation engines deliver strong ROI:
By following these best practices, you create a positive feedback loop: highly relevant and well-placed recommendations lead to more customer engagement and sales; those results justify further investment and refinement of personalisation; and continuous improvements keep the performance strong. In the end, this virtuous cycle maximises the return on investment from your recommendation engine.
Product recommendation engines, as a form of AI-driven personalisation, have proven to be powerful tools for modern retailers. They can drive higher conversion rates, larger basket sizes, and stronger customer loyalty – all contributing to improved financial performance. However, to truly capitalise on these benefits, businesses must keep a close eye on the ROI of their recommendation initiatives. It’s not enough to implement an algorithm and assume it’s adding value; the value must be measured, monitored, and cultivated.
By focusing on key metrics (like conversion lift, AOV, and CLV), using robust methods to attribute sales to recommendations, and continually optimising the system, retail leaders can clearly quantify the payoff from personalisation. When done right, product recommendations often pay for themselves many times over. It’s not uncommon to see ROI well above 100%, meaning the additional profit far exceeds the cost of the technology.
Yet, maximising that return requires more than flipping a switch. It calls for a thoughtful, customer-centric approach: aligning the recommendation engine tightly with shopper needs, integrating it seamlessly into the omnichannel customer experience, and refining it based on real performance data. Retailers who successfully leverage these engines will not only enjoy immediate revenue lifts, but also build deeper relationships with their customers – an advantage that compounds over time. This combination of short-term gains and long-term customer value is the essence of a strong retail personalisation ROI.
Below are distilled tools and takeaways for decision-makers to directly use when evaluating and comparing product recommendation engine initiatives. These checklists and frameworks summarise the key points from the discussion above in an executive-friendly format.
MetricROI Connection (Why It Matters)Conversion RateIndicates how well recommendations turn browsers into buyers. A higher conversion rate among users who see/click recommendations means the engine is directly driving more sales from existing traffic (boosting revenue without extra traffic acquisition costs).Average Order Value (AOV)Measures the increase in spending per transaction. When recommendations lead customers to spend more (upsells, cross-sells), the revenue per order rises – improving ROI by getting more value out of each customer visit.Basket Size (Items/Order)Tracks if customers buy more items per purchase. An effective engine often adds extra items to carts (e.g. accessories, complementary products). More items per order mean higher total sales and profit per transaction, lifting ROI.Customer Lifetime ValueReflects long-term revenue per customer. If personalisation brings customers back more often and increases their total spend over time, it boosts CLV. Higher CLV means greater return on the initial cost to acquire and serve each customer, significantly improving ROI in the long run.Revenue Attributed to RecsQuantifies sales directly linked to recommendation interactions. This shows the portion of revenue the engine is responsible for. Comparing this incremental revenue against the engine’s cost is the clearest way to evaluate ROI (e.g. “X% of revenue comes from recs” vs. “Y cost for the tool”).
How to use this table: Track these metrics before and after implementing a product recommendation engine (or between a test group vs. control group). Improvements in these metrics after introducing recommendations signal a positive impact. The greater the improvements, the higher the likely ROI. For instance, a jump in conversion rate from 2% to 2.5% after deploying the engine, or a rise in AOV from $50 to $60, directly translates into increased revenue that can be weighed against the investment cost.
By using these checklists and frameworks, executives can systematically evaluate the effectiveness of product recommendation engines and make informed decisions to enhance retail personalisation ROI. The goal is to translate the promise of AI-driven recommendations into tangible business results – and to keep optimising until the returns are truly compelling.