Sorry to sound dumb but I don't follow, you had your physical books in a bin? And you paid this teenager to categorise them into LT? What was the value for you. Again sorry it will be making me sound like an idiot asking this ;)
1. We were moving. They had to come off the shelves anyway.
2. I've got more books than shelves.
3. Until I figure out my book/shelve situation, the bins make it easy to keep the books out of the way in storage, but turn up a particular book when I need it.