The library system locally has self-checkout. The line is usually shorter than the manned checkout line--but it takes FOREVER. The computer is slow moving from screen to screen (poor wi-fi?) It reads RFID chips, and the self-checkout only reads one at a time, and each read takes a noticeable amount of time.
The manned checkout usually does 3 at a time, so is a lot faster and if you've got even more than just one book, it takes significantly less time. Their computer also doesn't have the intense lag that the self-checkout does.
I'd think making self-checkout appealing would involve making it appealing--you know, finding reasons that people would WANT to use it. I often do anyway because the library staff look so busy, but it leaves me frustrated and irritated. And I see a lot of people walk right by it and ignore it (it's a large station you must pass to get to the manned checkout)--I'm betting they've tried it and got so frustrated that they're not interested in using it any more.