How DOUXDS Uses Boost's Smart Cart and AI Cross-Sells to Turn Single-Product Buyers into Subscribers

DOUXDS is a men's performance skincare brand built around a simple insight: men's skin deserves better than bar soap and hope. Founded by Damon Dixon after 13 years of battling acne and dark marks, the line starts with the FLEX™ sonic vibrating face brush and fans out into a set of complementary formulas. WAR™ face wash. PRIME™ moisturizer. CRUSH™ bump serum. The MIRO™ towel. A subscription called The King's Plan.

That product ecosystem is the business model. A customer who buys just the brush is a good sale. A customer who adds the wash, then the moisturizer, then subscribes monthly. That's the business working the way it was designed.

But for years, the tools supposed to make that journey smooth were doing the opposite.

The real cost of a fragmented cart stack

Damon had been through the gauntlet. Multiple upsell and cross-sell apps, all the popular names on Shopify, each promising higher AOV. They worked, kind of. AOV went up while conversion went down.

"I've used so many upsell and cross sell apps over the years of running my brands (many of the popular ones). The issue with them is the UI/UX is terrible, the customization is limited, and the biggest thing is they either don't have carts or if they do, they're clunky. So sure AOV goes up but your CR likely goes down."

Most Shopify upsell apps bolt on a modal or inject an offer, but the cart experience underneath is either nonexistent or stitched together from a separate app with its own pricing tier. For DOUXDS, where the natural buying path moves from brush to face wash to moisturizer to full King Set to monthly subscription, every extra click and clunky drawer kills conversion.

He was paying for multiple apps to deliver a worse experience than having no apps at all.

"You may also need to download a separate cart app which has its own pricing tiers, making for a fragmented experience. This is why I left the last app ultimately."

Finding Boost

When Damon discovered Boost, he didn't schedule a demo and wait two weeks. He went straight to the founder.

"When I found Boost, I bugged the founder to let me use it as soon as possible!"

One app that replaced the entire fragmented stack. Cart, cross-sells, upsells, subscription switching, bundles. One install.

Smart Cart: reward tiers, AI cross-sells, and one-click subscription switching

At the center of the DOUXDS setup is Boost's Smart Cart.

Smart Cart supports up to 4 customizable reward tiers mixing discounts, free shipping, and free gifts. For DOUXDS, this is how a $69.99 brush purchase becomes a $129.99 King Set order. Unlock free shipping at the first tier. Add WAR™ face wash at a discount in the second. The third tier drops a free MIRO™ towel into the cart, and the fourth - the King Set - gets full bundle pricing. The Cart Reward Bar shows customers exactly how close they are to the next tier, styled to match the DOUXDS brand.

AI Recommendations & Cross-Sells look at what's already in the cart and suggest the logical next product in real time. Customer adds the FLEX™ brush? The cart surfaces WAR™ face wash, the formula designed to pair with it. Already has the brush and the wash? PRIME™ moisturizer appears. Cross-sells based on what's actually in the cart, not a generic bestseller list.

For DOUXDS's subscription business, the Switch to Subscription toggle sits right inside the cart. One click. No new page. A customer who came in for a one-time brush purchase can convert to The King's Plan monthly delivery without leaving the cart.

"Especially for brands with subscription or many complementary SKUs, the Boost cart makes switching to subscription super easy and upsells super intuitive."

Bundle Builder: The King Set, purpose-built

The King Set at $129.99 is brush, all formulas, and towel in one package. Boost's Bundle Builder turns that into a "build your own" experience where customers mix and match their way to the full routine.

DOUXDS runs three unique bundle builders with dedicated URLs. One for the main site. One optimized for email campaigns. A third built specifically for paid ad landing pages. Same product, different entry points, each tuned for the channel driving traffic.

Post-purchase

After checkout, Boost's Post-Purchase Upsells present a dedicated offer page. Not a popup. Not an email three hours later. A clean page with a two-step flow: first, offer more of what they just bought - another CRUSH™ bump serum, since they'll use it up. Then surface AI-powered recommendations or hand-picked complementary products they didn't grab. One-click accept, no re-entering payment info.

The team

"The team is full of A+ players. They helped me get my brand set up quickly and even make a few custom changes for me when it came to cross sells. Also just look at their own website and branding, their attention to detail is top notch."

The Boost team configured custom cross-sell logic for how DOUXDS customers actually shop. They mapped the brush-to-formula journey into the AI recommendations, tuned the reward tiers to match the brand's pricing, styled the Cart Reward Bar to match DOUXDS's look, and built custom cross-sell rendering when Damon asked.

Moneyboard

With Boost's Moneyboard, DOUXDS can see exactly where revenue is coming from. Broken down by feature. Which reward tier drives the most upgrades. How Smart Cart cross-sells perform versus post-purchase upsells. What percentage of customers convert from one-time to subscription via the in-cart toggle.

Flat pricing

Most upsell apps charge a percentage of the incremental revenue they generate. The better they work, the more you pay. Boost uses flat pricing. The cost is the cost, regardless of how much additional revenue flows through Smart Cart, bundles, or post-purchase offers. For a brand doing the volume DOUXDS does across 100,000+ customers, the savings add up.

"With most other upsell apps, you're paying a percentage of upsell revenue which is robbery."

Boost also replaces what used to require separate apps for cart, upsells, cross-sells, and subscription management. Fewer invoices and fewer things that can break.

"Boost is the perfect all in one solution to maximize your revenue and conversion rate at an unbeatable price and value. Make the switch, you won't regret it."

- Damon Dixon, Founder, DOUXDS

About DOUXDS

DOUXDS is a men's performance skincare brand founded by Damon Dixon in June 2020. After 13 years of struggling with acne and dark marks, and finding nothing on the market that actually worked, Damon invested over $1M in R&D alongside estheticians, engineers, and real customers. The result: the FLEX™ sonic vibrating face brush featuring medical-grade silicone bristles and anti-microbial silver-infused technology, backed by 26 clinical studies. The full product lineup includes WAR™ face wash, PRIME™ moisturizer, CRUSH™ bump serum, and the MIRO™ towel. Over 100,000 customers served. Every purchase is backed by a 90-day money-back guarantee. Keep the brush either way. Learn more at douxds.com.