I saw plastic post it notes on some 2 dollar shops recently, and saw how it is thin enough to fit in the inside cover of a textbook.
Since textbook publisher are already price gorging us students. Can't they at least spare us some useful tabs?
It means that while reading a chapter, instead of fumbling
for post it notes, we simply reach for the back of the book, and yank it out to place on a particular page in the textbook.
The tab should be thumb sized, with a small arrow in one end (so you can use it to point to a sentence).
There can also be guidelines for tabs, on each page, so you can use the tabs as chapter dividers. (this means publishers don't have to mark the edge of the book, to help viewers find their chapter quickly)
And hey! it also provides some planned obsolescent (after all, you can't replace the post-it notes in the back of the textbook)
p.s. don't forget to get the ones that allows you to write on it.