I just received an email from Amazon for shopping on Prime Day. You have to make a purchase of $10 and then they add $10 to your account.
Here are the terms: Offer only applies to physical products sold by Amazon.com. Offer does not apply to digital content. Offer only applies to products sold by Amazon.com Products sold by third-party sellers or other Amazon entities will not qualify for this offer, even if “fulfilled by Amazon.com” or “Prime Eligible”. Offer good while supplies last. Shipping charges and taxes may apply to discounted and free promotional items. Items must be purchased in a single order and shipped at the same speed to a single address. Offer limited to one per customer and account. Taxes, shipping and handling, and gift wrap charges do not apply when determining minimum purchase amount. The maximum benefit you may receive from this offer is $10. You will receive an e-mail from Amazon that indicates the dollar amount of the promotional credit and that the dollar amount of the credit has been added to your customer account. The e-mail will also provide instructions on how to redeem the promotional credit. Promotional code expires at 11:59 p.m. (PT) June 30, 2018. Promotional code only applies to orders of at least $10. May not be redeemed for Amazon Gift Cards. This offer is available to Prime members only.