Average order value is one of the most impactful metrics in ecommerce. A 10% increase in AOV has the same revenue effect as a 10% increase in traffic — but without the marketing cost. Upselling and cross-selling are the primary tactics for increasing AOV, and the app you choose to power these recommendations has a direct impact on results.
Rebuy and Bold are two popular approaches to upselling on Shopify. Rebuy is a newer, AI-powered personalisation engine. Bold is an established Shopify app developer with a suite of ecommerce tools including upsell functionality. Both can increase your AOV, but they differ significantly in sophistication, pricing, and approach.
Having implemented both across Shopify stores, I can say that the right choice depends on your budget, technical requirements, and how much you want to invest in personalisation. For a broader look at AOV strategies, see our guide on smart cart solutions for boosting AOV.
Why upselling matters
Upselling and cross-selling work because they present relevant additional products to customers who are already in a buying mindset. A customer adding a coffee grinder to their cart is a warm prospect for coffee beans. A customer buying a skincare serum is likely interested in the complementary moisturiser. The key word is relevant — irrelevant upsell offers annoy customers and can reduce conversion rates.
For UK ecommerce brands, the economics are compelling. If your current AOV is £45 and you increase it to £52 through effective upselling, that 15% lift compounds across every order. On 10,000 annual orders, that is an additional £70,000 in revenue without acquiring a single new customer. For strategies on increasing AOV specifically, see our guide to increasing average order value on Shopify.
Platform overview
Rebuy: AI-powered personalisation
Rebuy is a personalisation engine that uses machine learning to power product recommendations across the entire shopping journey. The platform analyses purchase patterns, browsing behaviour, cart composition, and customer attributes to generate recommendations that improve over time. Rebuy offers recommendation widgets for product pages, cart pages, checkout (Shopify Plus), and post-purchase, as well as a smart cart drawer with built-in upsell functionality.
Bold: established Shopify app suite
Bold Commerce is a well-established Shopify app developer that offers a suite of ecommerce tools. Bold Product Upsell (also called Bold Upsell) provides rule-based upsell and cross-sell offers that can be triggered based on cart contents, product type, collection, or customer tags. Bold also offers Bold Bundles and Bold Subscriptions as separate products. The upsell app is straightforward, affordable, and easy to configure.
Pricing comparison
Rebuy uses a performance-based pricing model. Plans start at $99/month, which includes up to $1,000 in Rebuy-generated revenue. As your Rebuy-attributed revenue grows, pricing scales accordingly. This model means you pay more as the platform generates more revenue for your store, which aligns incentives.
Bold Product Upsell starts at approximately $9.99/month with additional pricing tiers based on the number of upsell views. Bold's pricing is significantly lower than Rebuy's, making it accessible for smaller stores. However, the feature depth and AI capabilities are proportionally simpler.
The pricing gap is substantial, but the comparison should factor in ROI. If Rebuy generates £5,000 in additional monthly revenue and costs £300/month, while Bold generates £1,500 in additional revenue and costs £10/month, both deliver strong ROI but Rebuy delivers more absolute profit despite the higher cost.
AI-powered recommendations
Rebuy's AI engine analyses your store's purchase data, product relationships, browsing patterns, and customer segments to generate personalised recommendations. The system identifies products frequently bought together, products that appeal to similar customer profiles, and items that complement the current cart contents. Recommendations improve over time as the AI processes more transaction data.
Bold uses rule-based logic. You define which products to recommend based on triggers like cart contents, specific products, collections, or customer tags. This approach gives you precise control over what is recommended, but it requires manual configuration and does not adapt automatically based on customer behaviour.
For stores with large catalogues (500+ products), Rebuy's AI approach is significantly more practical than manually configuring rules for every product combination. For stores with smaller catalogues where you know exactly which products complement each other, Bold's rule-based approach can be equally effective with less cost.
Placement options
Rebuy offers recommendation widgets across multiple touchpoints: product pages, cart page, cart drawer, checkout page (Shopify Plus), post-purchase page, thank you page, and dedicated landing pages. The smart cart drawer is particularly effective, combining a slide-out cart with contextual upsell recommendations, free shipping progress bars, and gift with purchase offers.
Bold primarily offers product page and cart page popups for upsell offers. The placement options are more limited than Rebuy's, focusing on key decision points rather than the full shopping journey.
Checkout upsells
Checkout upsells — offers presented during the checkout process — are available on Shopify Plus through Checkout Extensions. Rebuy supports checkout upsells with AI-powered recommendations. Bold has more limited checkout integration. For Shopify Plus merchants, checkout upsells represent a significant revenue opportunity because the customer has already committed to purchasing. For Shopify development and app integration, checkout upsells require careful implementation to avoid disrupting the purchase flow.
Post-purchase offers
Post-purchase upsells (offers shown after payment but before the confirmation page) are a high-converting placement because the customer has already completed their purchase and can add items with a single click without re-entering payment details.
Rebuy offers post-purchase upsell pages with AI-powered recommendations. Bold has post-purchase capabilities through its suite of tools. Both platforms can present offers at this high-intent moment, but Rebuy's AI makes the offers more contextually relevant.
A/B testing
Rebuy includes built-in A/B testing for recommendation widgets, allowing you to test different algorithms, placements, and offer types. Bold offers more limited testing capabilities, typically requiring manual comparison of results across different offer configurations.
Analytics and ROI tracking
Rebuy provides detailed analytics showing revenue generated by each widget, conversion rates for different recommendation types, and overall ROI metrics. The dashboard makes it straightforward to see which touchpoints and offer types generate the most additional revenue.
Bold tracks basic upsell metrics including offer views, acceptance rates, and revenue generated. The analytics are functional but less granular than Rebuy's reporting.
Integrations
Rebuy integrates with Klaviyo, Recharge, Stamped, Okendo, and other Shopify apps. These integrations enable personalised recommendations based on subscription status, review data, and email engagement. Bold integrates with other Bold products (Subscriptions, Bundles, Loyalty) and select third-party apps. Both integrate with the core Shopify app ecosystem.
Store performance
Rebuy's widgets load asynchronously and are optimised for performance, but the AI recommendation engine does add some page weight. Bold's simpler implementation typically has a lighter performance footprint. For performance-sensitive stores, both apps should be tested for their impact on Core Web Vitals.
The verdict
Choose Rebuy if:
- You want AI-powered product recommendations that improve over time
- You have a large product catalogue where manual rule configuration is impractical
- You want upsell touchpoints across the entire shopping journey
- You are on Shopify Plus and want checkout and post-purchase upsells
- You prioritise data-driven optimisation with A/B testing and detailed analytics
- The revenue generated will justify the higher price point
Choose Bold if:
- Budget is a primary concern and you want effective upselling at a low cost
- Your product catalogue is small and you know exactly which products to cross-sell
- You want a simple, quick-to-implement upsell solution
- Rule-based recommendations are sufficient for your needs
- You use other Bold products and want a unified ecosystem
- You are an early-stage brand testing the upselling model
For most growing UK Shopify brands, Rebuy delivers a stronger ROI through AI-powered recommendations that adapt and improve. For smaller brands with limited budgets and straightforward upsell needs, Bold provides effective functionality at a fraction of the cost.
If you are looking to increase average order value through better upselling and cross-selling, get in touch. We can help you choose and implement the right tools as part of your Shopify store and app ecosystem.