I'm really surprised that nobody made a product with this idea/concept already. I probably have a few hundred unread items across all ex-popular and now-popular bookmarking services (Pocket, Safari's Reading List, now-dead Google Reader, delicious). For me, the big problem always was that I bookmark interesting reads, but then I don't come back to it. Or I bookmark it, actually read it, but then never come back to it to check out what's new stories of the author.