Samuel Hess recently shared something that caught my attention: "A subtle nudge on the quantity selector = +1.80% ARPU lift on women's product pages." He went on to explain that they "added a progress bar indicator showing how bumping up quantity unlocks free shipping right on the PDP." That simple line is a masterclass in modern CRO: take an incentive shoppers already care about (free shipping) and make the path to it unmistakably clear.

In this post, I want to expand on what Samuel shared, why it worked (especially for women’s sneakers and apparel), and how you can test a similar idea without accidentally hurting desktop performance or margin.

What Samuel Hess tested (and what happened)

Samuel’s change was not a massive redesign. It was a small UI cue placed exactly where purchase intent concentrates: the quantity selector on the product detail page (PDP). The tweak: a progress bar that visually indicates how close a shopper is to unlocking free shipping as they increase quantity.

The reported results for all users were strong for such a small change:

ARPU: +1.80%
Conversion rate: +1.05%
AOV: +0.74%

He also noted a key segmentation insight: mobile users responded particularly well (+2.63% ARPU), while desktop dipped slightly but remained statistically insignificant.

Key idea: free shipping was already available, but the progress toward it became visible and actionable.

Why this works: make the reward concrete, not abstract

Samuel called out the psychology directly: the goal gradient effect. In plain English, people accelerate as they feel closer to a goal. Loyalty punch cards, progress rings, and "only 2 steps left" checkouts all lean on the same mechanism.

Free shipping thresholds can be weirdly invisible in ecommerce. Many stores mention them in a top bar, footer, cart, or policy page. Customers may vaguely know "free shipping exists," but they do not feel the finish line.

A progress bar near quantity changes that:

It turns a policy into a target.
It creates a micro-game: "I’m almost there."
It reduces mental math (especially on mobile).
It reframes adding quantity as gaining value, not spending more.

Samuel’s phrasing matters here: "No more vague incentives; this made the reward crystal clear, turning browsers into bulk buyers." The improvement is not only persuasion, it is clarity.

Why it may work especially well on women’s sneakers and apparel

Samuel also shared an important nuance: women’s items can feel personal and size-sensitive, and that can create hesitation around buying multiple units. If you sell apparel or footwear, you have probably seen this behavior:

Shoppers worry about sizing.
They hesitate to buy duplicates because returns feel likely.
They may want to "try one" first.

So why would a quantity nudge work at all here?

Because the nudge is not "buy more because we want you to." It is "buy one more and you unlock a tangible benefit." That reframes the decision from indulgence to optimization. "Just one more" starts to feel like a smart move, not a risky one.

Also, women’s categories often include items people genuinely do buy in multiples (socks, basics, leggings, tees) and gifting behavior can be higher around apparel. A visible threshold can prompt shoppers to combine needs: one for me, one as a backup, one as a gift.

The subtle win: the interface reduces hesitation by replacing uncertainty with a clear trade.

Why mobile likely outperformed desktop

Samuel noted mobile users loved it. That aligns with how mobile shopping works:

Less screen space means fewer cues compete for attention.
Mobile users avoid extra steps (like checking shipping details elsewhere).
A progress bar is "at-a-glance" information.

Desktop shoppers, on the other hand, may already notice free shipping banners, cart sidebars, or header messaging more often. Desktop users may also be more deliberate and compare across tabs, so the same nudge can be less incremental.

If you replicate this, treat device as a first-class segment. It is completely plausible that placement or design needs to differ by device.

The real takeaway: visualize the path, do not discount the product

Samuel’s closing takeaway is worth repeating in expanded form: free shipping is table stakes in many categories, but visualizing the path to it is what can lift AOV and ARPU without running discounts.

Discounts are blunt instruments. They train customers to wait, compress margins, and can degrade brand perception. A "path visualization" nudge can be cleaner:

You are not reducing price.
You are increasing perceived value.
You are making an existing benefit easier to capture.

That is exactly the kind of CRO win that scales across product lines.

How to test a free shipping progress bar on your PDPs

If you want to apply Samuel’s idea, here is a practical test plan.

1) Choose the right products first

Start where variable quantity actually makes sense:

Consumables or replenishment items
Basics that people buy in multiples
Bundlable items (colors, sizes, family packs)
Categories where shipping cost is a known friction point

If your products are high-consideration, expensive, or rarely purchased in multiples, a quantity nudge may not be your best first test.

2) Decide the "finish line" and messaging

Your threshold should be simple and truthful. Examples:

"Add 1 more to unlock free shipping"
"$X away from free shipping"
"Free shipping at 3+ items"

Keep the message consistent everywhere (PDP, cart, checkout). Mismatches destroy trust.

3) Place it where intent is highest

Samuel placed it at the quantity selector. That is smart because it connects action (increase quantity) to reward (free shipping) without forcing the shopper to hunt.

Consider testing placements:

Directly under quantity
Inline within the quantity component
Near the Add to cart button

On mobile, prioritize visibility without adding clutter or pushing key elements below the fold.

4) Measure beyond AOV

Samuel reported ARPU, conversion rate, and AOV. If you copy this test, also track:

Gross margin per visitor (shipping is a real cost)
Return rate (especially in apparel)
Units per transaction
Revenue per session by device
Downstream effects like customer support tickets about shipping

AOV going up is great. Profit going up is the goal.

5) Segment aggressively and sanity-check desktop

Because Samuel saw a slight desktop dip (insignificant), do not assume your result will be identical. Desktop shoppers may respond differently to visuals, density, and competing messaging.

If desktop underperforms, experiment with:

A simpler bar (less visual weight)
Text-only "you’re X away" messaging
Showing the progress in cart instead of PDP

Common pitfalls (and how to avoid them)

A progress bar can backfire if:

The threshold feels unattainable (too high)
The bar is visually noisy or looks like an ad
Free shipping terms are complicated (exclusions, regions)
The offer conflicts with promos (coupon + free ship rules)

Keep it clean, honest, and easy to understand in one glance.

Closing thought

What I like most about Samuel Hess’s example is that it treats CRO as behavioral design, not just button color tweaks. The experiment connected motivation (free shipping) to an immediate, concrete action (increase quantity) and used a proven psychological effect (goal gradient) to do it.

If you sell products where customers can buy more than one, this is the kind of test that can lift revenue without racing to the bottom on discounts. As Samuel put it, free shipping is table stakes. Showing shoppers the path to it can be the accelerator.

This blog post expands on a viral LinkedIn post by Samuel Hess, Boost Revenue Per User by 10% in < 6 Months | Over $248M added with A/B-Tests for HelloFresh, SNOCKS, and 200+ other DTC brands. View the original LinkedIn post →