Price rounding is a default Shopify setting that can cause an unfavorable survey experience for foreign backers. The purpose of this setting is to create a more "stable" price on products but it can require backers to pay a very small amount (e.g. $.03) before they can complete their survey. As such, we strongly recommend disabling price rounding when using discounts for surveys.

More detailed explanation:

Currency conversions can cause product prices to have inconsistent price endings (e.g. $10.00 vs 13.57). When a discount with a fixed amount—like those used for surveys—is issued on Shopify, the amount off a product/order is defined by the store's default currency. If rounding rules are enabled, a discount for $10.00 may not cover the actual cost of a product thereby requiring a backer to pay any difference.

Example:

$10.00 USD = $13.57 CAD

If price rounding is enabled, the price for a Canadian backer may be $13.60.

If a discount code of $10.00 is issued it will be equal to $13.57 CAD. If the product costs $13.60 CAD because of the enabled rounding rules, this will result in a balance of $.02 USD being owed.

Learn more about price rounding on Shopify.