I used to pile up my new pbooks beside my bed (that's where I do most of my reading) and when the pile was perilously high I'd stop buying until I reduced the pile.
Now that I buy ebooks, there is no bedside pile to remind me that I have more than enough to read. Honestly, I could stop buying ebooks and still have enough to read for at least five years. But it's soooo easy to buy ebooks that it's difficult for me to stop. And coming here and seeing recommendations doesn't help, either.