The best choice depends on your margins, average order value, and what you want the offer to accomplish. A larger-looking discount can improve clicks and conversions, but the discount still needs to make sense for your business.
A simple rule of thumb
When the order value is under $100, a percentage discount often feels more compelling. For example, 25% off a $75 order can look stronger than $18.75 off, even though the value is the same.
When the order value is over $100, a dollar amount discount often feels more tangible. For example, $75 off a $300 order can look stronger than 25% off, even though the value is the same.
How to choose for your store
Use a percentage discount when you want the offer to feel simple, flexible, and broadly useful across different cart sizes.
Use a dollar amount discount when you want the savings to feel concrete or when you are encouraging customers to reach a specific minimum spend.
Use a minimum order value when you need to protect margins or increase average order value.
If you are unsure which one to use, start with the option that best matches your typical order value, then compare performance over time. The right answer may be different for a first-purchase offer, a repeat-purchase offer, and a high-value cart incentive.