Bookbub is a system offering daily e-book deals. I've been a user for a month now and quite like it. Prices range from Free on up to 2.99, but is most often just .99 or 1.99.
It works like this.
Sign up at at www.bookbub.com. You'll need to give them an email address and remember a password for the account.
Select your preferred e-book vendor(s). They have a few you can mix and match among, including all the major sources.
Choose your categories of interest. Being a cooking site, of course, I selected Cooking as well as other choices.
Similarly, you'll have a chance to mark authors you like.
Save your account information and wait for the daily email. You'll get offers in the major categories you selected most every day. This means I see a heavily discounted cookbook offer every day in my email. These are not usually the latest releases, and occasionally they're just self-published authors so do pay attention to the details.
I look at the offers, and most days just send it to my trash bin. But a few times a month, the right deal comes along and I grow my personal library.