4 builders who never spoke to each other

Fix the checkout details that cost you the sale

Measured tests on a donation flow found the biggest wins in details nobody argues about: making the recurring option the preselected default rather than asking people to switch, never pre-ticking anything that changes the number printed on the pay button, and not interrupting a completed purchase with a modal. Offer a low fee route such as bank debit for your largest payers and a wallet option for buyers who will not type card details. Have the checkout absorb sales tax so the advertised price is the price.

The method

1. 01

   Take PayPal alongside cards, because a share of buyers will not stop to type card details.

2. 02

   Offer bank debit alongside cards so your largest payers have a low-fee route that is easier than posting a cheque.

3. 03

   Ask buyers to cover your payment processing fees, but leave the box unticked so the choice is theirs.

4. 04

   Never pre-tick an add-on that changes the number printed on your pay button. People baulk at being charged something other than what they chose.

5. 05

   Do not interrupt a completed purchase with a modal offering to convert it into a subscription. The added step costs you more than the subscriptions gain.

What it returned

• $5

  ACH fees are capped at $5 where card fees run around 2%, and adding ACH is estimated to save GiveDirectly $50,000 a year.

• 85%

  Unticking the default cut fee coverage from 85% of donors to 60%, but the conversion penalty vanished, and the shipped version brings in an extra $200,000 a year against roughly $400,000 of annual processing fees.

• 6%

  With a pre-ticked box to cover payment processing fees, conversion ran 6% below the control, although 85% of those who did finish left the box ticked.

• Phoenix had no PayPal option and the founder now says to implement it.

Sources

• Why I bought your softwareJustin Jackson · justinjackson.ca · How to get people to buy your software (or SaaS) · undated
• How I custom-built my online course (tech stack, onboarding, costs, screenshots) - Rob HopeRob Hope · robhope.com · Payments: Lemon Squeezy · 2025-05-29
• Phoenix: Failed to Keep It Stupidly SimpleEnrique Benitez · failory.com · What did you learn? · undated
• How GiveDirectly increased donations by over $3 million/year through experimentationOlivia Chen · lennysnewsletter.com · Tiny changes can add up to a big difference · 2024-12-03