(Update 11/13/23: Reloads are now minimum $1 as well.)
The minimum gift card possible to buy on Amazon.com is now $1, up from the previous minimum of $.50. You can still reload your Amazon gift card balance with just $.50.
Small Amazon loads are a useful way of meeting minimum spend thresholds on bank accounts or credit cards that require a certain number of transactions. Many banks require transactions to keep the account fee-free, and the Everyday Preferred card from Amex requires 30 transactions in order to be eligible for the 50% bonus the card offers.
There’s a good chance that the reloads will change eventually too. For now, just shift over from gift cards to reloads if you haven’t already.
HT: Reddit

