Where guests look
Next to the router, on the back of the door, on the bedside table and in the welcome folder. A code in each spot with a one-word label works better than a single code on a crowded information sheet.
Update between stays
The guidebook changes with the seasons; the printed frame on the wall does not. With an editable code you point it at the new PDF or page and every room follows.
Remember that a Wi-Fi code contains the password itself: if you change the password, print a new Wi-Fi code.
Learn what guests use
Scan stats show which codes guests open and when, so you can see whether anyone reads the guidebook or whether the review request at check-out gets scanned.