Explain what is the benefit of automatic hold checkout for ebooks.
Thanks for asking! Like most things, the benefit of the automatic hold checkout feature is a little bit up to the eye of the beholder. Over time, Overdrive has shifted from automatic hold checkout being an option to being the default setting; users can opt out of it if they wish. (See this article for instructions.)
If it doesn't seem like automatic checkout saves much time (users still need to sign in and choose what format they want to download the ebook) consider that in the 'original' setup users had to get the hold notification, sign in to their account, confirm the checkout and then proceed to download - for the vast majority of users it was nothing but an extra step. There was also the problem that the window to check out a digital hold once it came available was relatively short at only three days / 72 hours; people who didn't or couldn't check their email every day were frequently losing their place in line.
I'd have to say that's the biggest benefit of automatic hold checkout; power users might be aware of and value the 3-day hold window to optimize their reading time, but automatic checkout avoids the much bigger disappointment of a user missing a book they've waited for. If you prefer to check out your holds manually, you can still opt back to it using the instructions above.