I received an email announcing a promotion from Citibank on my Citi Prestige card. I do not know if this deal is being offered on other Citi credit cards too. There is no registration link, but the email states that the promotional offer only applies to the account with the last four numbers referenced in the email. Interestingly, I don’t see any exclusions, such as gift card purchases, listed in the terms and conditions (see below).
this is the offer in a nutshell:
Earn a one‑time $30 statement credit after you make at least three Amazon.com purchases of $30 or more each with your Citi® card between 11/14/2018 and 12/31/2018.
Here are the terms and conditions:
You will receive a one‑time $30 statement credit after you make at least three purchases of $30 or more each at Amazon.com with your Citi credit card. Your purchases must post to your account between 11/14/2018 and 12/31/2018. The statement credit will be applied to your account within 2 billing cycles after the eligible purchases are posted.
In order to qualify for this offer, the account must be open and current at all times. If your account is closed for any reason, including if you convert to another card product, you may no longer be eligible for this offer. This promotional offer is non-transferrable and applies to the account ending in the last 4 digits referenced in this offer.