I've been eyeing this Sephora by OPI nail polish in Metro Chic ($9) for enough time that the Sephora employees probably recognize me every time I skulk in to see if it's back in stock. It never is — my Sephora spies tell me that demand has far outreached the supply — but I keep looking. And yet, I won't sign up for a waiting list. Too much commitment. When it comes to beauty products, will you sign up on a waiting list, or do you take your chances?