Nookpress (Barnes and Noble) has many pluses on its side, such Read in me Store program, Lend Me program, Samples, eGifting, and Affiliates program, and check out the link for the programs.
https://www.nookpress.com/support
But I thought KDP Select program offered more intriguing options. I've cut and pasted the reasons why from Amazon's Authorcentral.com site.
Why Enroll in KDP Select?
- Earn your share of the KDP Select Global Fund amount when readers choose and read more than 10% of your book from Kindle Unlimited, or borrow your book from the Kindle Owners’ Lending Library. Plus, earn 70% royalty for sales to customers in Japan, India, Brazil and Mexico.
- Choose between two great promotional tools: Kindle Countdown Deals, time-bound promotional discounting for your book while earning royalties; or Free Book Promotion where readers worldwide can get your book free for a limited time.
- Help readers discover your books by making them available through Kindle Unlimited in the U.S, U.K., Germany, Italy, and Spain and the Kindle Owners’ Lending Library (KOLL) in the U.S, U.K., Germany, France, and Japan.
If you choose KDP select program, you cannot sell your e-books elsewhere on the web. There are additional limitations, so please check it out before you try it, too.
There are many KDP select videos on Youtube, and I've watched a quite a few, but to be honest, I didn't find a lot of them useful. Most were self-promotional videos, and I had fun watching them, fantasizing about seeing one of my own one day, but I didn't find them overly useful. BUT since there are so many videos available, I could have veered off at a point and completely missed videos that are quite useful and helpful.