An unexplained code makes totals hard to understand. A prominent empty field can also invite shoppers to leave the purchase to search for a code.
Discount codes: eligibility and feedback
Keep the promo field out of the main task. When used, explain eligible items and how the discount changes the total.
Research context: Baymard · Checkout fields and apply behavior ↗
A collapsed entry fits stores that support codes. An automatic promotion should not require shoppers to discover and type a code.
Try the pattern
Task and expected result
- 01
Open Have a lab code? without changing the basket. Enter LAB10 and leave the field: show terms and the mug discount.
- 02
Use an unknown code: show a specific error, preserve the code and basket, and apply no discount.
- 03
Add an accessory: discount only mugs. Compare subtotal, discount and new total.
- 04
Remove the code: restore the full total. No control charges a payment.
How to investigate value
Measure confirmed, deduplicated outcomes per eligible checkout start. Define paid orders and accepted credit orders separately.
Watch for side effects
Payment errors, duplicate orders, incorrect totals, unclear arrival dates and discount cost. A pay click is only an attempt.
This is a proposed investigation, not a measured result. Choose one hypothesis and define the audience before testing.
Build a measurement plan for this concept ↗