Replace 'Add to Cart' with 'Buy 1 / Buy 2 / Buy 3'

Most PDPs are built around a single question: should I buy this? The button says "Add to Cart" and the buyer answers yes or no.

But what if you reframed the decision entirely? Instead of should I buy, ask how many should I buy?

Research across 37 experiments found that replacing a single CTA with multiple quantity-specific buttons (Buy 1 / Buy 2 / Buy 5) increased conversions by 14% on average and total sales volume by up to 28%.

Why it works

When people commit to buying, they tend to split the decision into two stages: first, "do I want this?" - then "how many?" When you show quantity CTAs, you're effectively skipping stage one. The buyer is already answering stage two, which means they're psychologically further down the funnel.

It also anchors behaviour. Showing "Buy 3" as a natural option makes buying three feel normal, not excessive.

This isn't for every product

The technique works best for products that have a natural multi-unit logic:

• Supplements or vitamins
• Coffee or tea
• Skincare consumables (serums, cleansers)
• Cleaning products
• Socks, underwear, basics

It doesn't translate well to considered purchases where buying more than one unit is unusual - shoes, electronics, outerwear.

What to test

Start with three options. Don't just add more - three is the optimal number of choices before decision fatigue creeps in. Test which quantities resonate: "Buy 1 / Buy 2 / Buy 3" vs "Buy 1 / Buy 3 / Buy 6" depending on your product's natural repurchase cycle.

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Research: Amir, O. & Duke, K. (2022). Marketing Science, 41(3). Rotman School of Management, University of Toronto & UC San Diego.