Draft2Digital offers a very cost-effective distribution route for ebooks (print on demand also, but that service is still in beta, for various reasons). Its sale channels cover all of the large ebook retailers. It has a very simple and attractive service proposition:

We are Self-Publishing with Support. Your book is your priority. Our priority is you. We build tools and services that let you focus on writing while we take care of layout, publishing, distribution, print-on-demand paperbacks, and more. Keep writing. We’re here for the rest.

In a long and very informative blog post, author services firm Reedsy describes them as “The gold standard for self-publishing aggregators, Draft2Digital distinguishes itself with excellent customer service and a user-friendly interface. They’re the best way to sell your book with dozens of retailers without tearing your hair out.”

Kindlepreneur also has a largely positive review that dives into the details of uploading a new title and how the royalty payments and update fees work.

Users discuss vcry specific pros and cons of the service on a reddit thread. Important note: the 10% Draft2Digital fee is charged on retail price, not on profit, and comes on top of the share taken by the end seller.

Writers Weekly has published a number of very negative user reviews that indicate some administrative problems.

Plenty of users had complaints about the non-payment of royalties.
Draft2Digital books cannot access Amazon advertising or other Amazon sales tools.

In summary, a service that will be useful to many authors, but go in with your eyes open and aware of the moderate drawbacks, especially the Amazon advertising issue.