1. Amazon.com Inc.
2. Apple Inc.
3. BookFlow
4. bookGeeks
5. Bookish Santa Private Limited
6. Draft2Digital
7. Elliott Bay Book Company
8. Gazelle Book Services Ltd
9. Google LLC by Alphabet Inc.
10. Hachette Book Group
11. HarperCollins Publishers LLC
12. IDW Publishing
13. Lulu Press Inc.
14. MacMillan Publishers
15. Morris Publishing
16. Pearson PLC
17. Penguin Random House LLC
18. Pustak Kosh
19. Rakuten Kobo Inc.
20. RPI Print Inc
21. Scholastic Inc.
22. Scribd Inc.
23. Simon & Schuster Inc.
24. Used Books Factory
25. Worldwide Book Services Ltd