PDP Size Selection Area Optimization: $386K/Month Case Study

The buy box is where decisions happen. Make every element earn its place.

We restructured the product page size selection area for an 8-figure luxury pajama brand. Moved elements around. Made fit guidance more visible. Turned a passive dropdown into an active CTA.

Results: +$386,441/mo revenue.

No new features. Just better arrangement of what was already there.

The Problem With Cluttered Buy Boxes

The control PDP had all the right elements: price, reviews, size guide, color selector, social proof ("In 102 Carts"). But they were scattered. Price on one line. Reviews on another. Size guide tucked away. The "Select Size" dropdown was passive, waiting for customers to interact.

For a $298 dress, customers have questions before clicking "Add to Cart." Will this fit? What size should I get? Is this worth the price?

The control layout didn't answer those questions efficiently. Customers had to hunt for information instead of flowing toward purchase.

The Hypothesis

By restructuring the PDP's size selection area—elevating price visibility, replacing the passive size dropdown with a prominent size-action CTA, surfacing fit guidance (size guide + fit information) closer to the point of decision, and reinforcing social proof with clearer copy—we'll reduce sizing-related purchase hesitation and increase add-to-cart rate.

Test Setup

Component: Product Page
Location: Size selection area
Platform: Intelligems
Test Type: A/B/n with 4 variations

Control

Standard PDP layout:

• Product name
• Star rating + "11 Reviews" (separate line)
• Price "$298" (separate line)
• "Or 4 installments of $74.5 /mo with Shop Pay"
• "Color: Ink" with swatch
• "Size Guide" link (right-aligned, easy to miss)
• "Select Size" dropdown
• "In 102 Carts" at bottom

Elements spread out. Passive size selection. Fit guidance not prominent.

Variation 1: Restructured Layout (Winner)

Reorganized buy box:

• Product name
• Price "$298" inline with "★★★★★ 11 Reviews"
• "Or 4 installments of $74.5 /mo with Shop Pay" (Shop Pay logo prominent)
• "Color: Ink" with swatch
• "Size and Fit Information" + "Size Guide" links on same row
• "Select Size" dropdown
• "In 102 Carts" social proof moved up
• "SELECT SIZE" button (prominent CTA)

Price and reviews together. Fit guidance surfaced. Active CTA instead of passive dropdown.

Variation 2: Enhanced Social Proof Copy

Similar restructured layout. Changed social proof copy to "102 People Have This in Their Cart" (more specific than "In 102 Carts"). Same fit guidance links. "SELECT SIZE" button.

Variation 3: Price Repositioned + Gift With Purchase

Different approach:

• Added "Reviews Summary" link next to reviews
• "102 People Have This in Their Cart"
• Price "$298" moved down near size selector
• "Find my size" + "Size Guide" links
• Size dropdown with "ADD TO CART" button inline
• "2025 GIFT WITH PURCHASE" promo visible in the first fold.
  

Results

Winner: Variation 1 (Restructured Layout)

Metric	Improvement
Monthly Revenue	+$386,441

The cleanest restructure won.

Why It Worked

1. Price and reviews together create instant validation

"$298 ★★★★★ 11 Reviews" on one line answers two questions at once: What does it cost? Is it good?

In the control, customers saw price, then had to look elsewhere for reviews. In V1, they see both together. The reviews justify the price immediately.

2. "Size and Fit Information" reduces sizing anxiety

For apparel at $298, wrong size = return hassle or wasted money. Customers need confidence before buying.

Adding "Size and Fit Information" alongside "Size Guide" gave customers two clear paths to get sizing help. More visible = more used = less hesitation.

3. "SELECT SIZE" button beats passive dropdown

A dropdown says "here's an option." A button says "take this action."

The "SELECT SIZE" CTA made size selection feel like the next step in a process, not an optional interaction. It guided customers toward the purchase flow.

4. Moving social proof up increased visibility

"In 102 Carts" at the bottom of the control was easy to miss. Moving it up meant more customers saw it before deciding.

Social proof only works if people see it. Position matters as much as copy.

5. No new features, just better organization

V1 didn't add anything that wasn't already on the page. It just arranged existing elements more effectively.

Price + reviews together. Fit guidance visible. CTA prominent. Social proof positioned. Same ingredients, better recipe.

What This Means for PDP Optimization

Before adding features, optimize your layout. The information customers need might already be there—just not where they can find it.

Principles from this test:

• Group related information: Price + reviews, size + fit guidance
• Make guidance visible: Don't hide size guides and fit info
• Use active CTAs: Buttons beat passive dropdowns
• Position social proof strategically: Above the fold, near decisions
• Resist adding complexity: More isn't always better

FAQ

Why didn't the enhanced social proof copy (V2) win?

"102 People Have This in Their Cart" vs "In 102 Carts" is a subtle difference. Both communicate the same thing. The copy change alone wasn't enough to beat V1's full restructure.

How do you decide what to group together?

Think about customer questions and when they arise:

• "Is this worth the price?" → Price + reviews together
• "Will this fit?" → Size selector + fit guidance together
• "Should I buy now?" → Social proof near CTA

Group elements that answer related questions.

Does the "SELECT SIZE" button add an extra click?

Yes, technically. But it clarifies the flow. Customers know: select size → then add to cart.

The control's passive dropdown left customers wondering what to do next. The button made it obvious.

How much of the lift came from layout vs. the CTA change?

Hard to isolate without additional testing. But the combination clearly worked.

Layout and CTA reinforce each other. Better organization makes the CTA more effective. A clear CTA makes the organization feel intentional.

This test was run using Intelligems as part of a CONVERTIBLES personalization program. Want to see what PDP optimization could do for your store? Book a call to get 3 personalized recommendations for your store.