What are some alternatives?
When comparing Marvelous DB and Comixology Unlimited, you can also consider the following products
Marvel (Comics) API - Create awesome stuff with the world's greatest comic API
GlobalComix - Professional Comics Publishing
Comic Cruncher - Visualize appearances per year of comic book characters 💥
Piperka - Webcomics listing and subscription manager
Storyboard - Press kit platform
LINE Webtoon - LINE Webtoon is a digital comics platform with various comics for free on web and mobile.