You can read a whole load more about it on their website (do visit - it's well worth your while).
In a nutshell:
- There are no fees for you to pay. It won't cost you anything - not a cent.
- Your books will sell at exactly the same price you have them listed on Amazon
- You will receive exactly the same percentage royalties as if it were an Amazon (KDP) sale
- Your book will be converted into both ePub and PDF and sold alongside the Kindle format - this gives you the maximum opportunity for sales
- There's no charge for this conversion although Any Subject Books will expect you to keep your book with them a while to give them a chance to recoup their formatting costs
- You'll receive your royalties fortnightly - that's a lot quicker than Amazon or Smashwords pay!
- Payments are made direct to your Paypal account
- Full transparency operates
- You don't lose your independence, you don't need to sign up to publish through them nor do you assign any part of your copyright
- You don't need to buy ISBN's although they can supply them if you want
Basically, there's nothing to lose and everything to gain. Even if you only sold 100 copies, that's 100 readers you'd never have had otherwise.