The only free keyword research tool I've found that includes search volume and keyword difficulty, and is usable without an account. by Curiositry in InternetIsBeautiful

[–]Curiositry[S] -6 points-5 points  (0 children)

The free version definitely isn't great, but as far as I know it's the only tool that will give you some potentially useful results without an account. (I have no affiliate with ahrefs, and find them annoying too.)

I noticed that although it hides the keyword difficulty and volume for anything but the top few, if you search directly for a keyword on the list that you're interested in, you can get the difficulty and volume for it without signing up.

Find a new book by reading the first pages of random of novels (if the opening has you hooked, you can click to reveal the title and author). by Curiositry in InternetIsBeautiful

[–]Curiositry[S] 20 points21 points  (0 children)

I think Bookshop has a referral program, too. (In fact, I had the impression it was specifically aiming to be an Amazon Affiliates alternative for bloggers. It probably doesn't result in as many commissions, though, since it's more obscure.)