Goodreads giveaway questions

I’m preparing to open my Goodreads giveaway for my upcoming release. How many ebook copies should I offer?

Thomas says this in a 2022 article: “I’d encourage you to give away as many copies as possible so you can get as many reviews as possible.” That makes sense, but I’m not sure how many entrants I’ll have. If I offer the full hundred copies and only get that many entrants, then everyone wins a copy and no one goes on to actually buy the book…which is one of the reasons I’m doing the giveaway.

So maybe a better question is how many entrants I should expect. I have 500 followers on Goodreads who will be notified of the giveaway, and about 1,000 email subscribers (with overlap between those two groups). Any idea what an average entrants number looks like?

Also, has anyone had success with using a Goodreads giveaway to increase interest in a backlist book? I’m considering running a giveaway of my first-in-series too so it will pull more readers into the series during my launch window for the second book.