Using your Amazon.com account on comiXology lets you read many Kindle-purchased comics and gives access to future comiXology features, like better recommendations. Most comics purchased on Kindle are readable on comiXology, with more added weekly. Books that will sync over to comiXology for reading are seen with a "Kindle + ComiXology badge" on Amazon.
If you used an older comiXology username in the past to use comiXology, you can connect it with your Amazon login at comixology.com/merge. After that, you will use your Amazon account to log-in to all comiXology websites and apps. Your comiXology username is riding off into the sunset!
You’ll use the same payment methods on comiXology as you do on Amazon. We will be retiring other legacy payment options once you merge.
You shouldn’t switch to login to comiXology with your Amazon account if you cannot update to the most recent comiXology app (3.8 or later) on your device.