This varies from user to user and depends on the intensity of use. There are Bambooks that already last 5 years. Of course, these have been treated with care so the lifespan is longer.
With normal use, the pages stay smooth and easy to write on without losing quality. One Bambook can replace many traditional paper notebooks. Use the Bambook marker, wipe the pages with a slightly damp cloth and store your notebook properly to get the most out of it.