When tears and crying get the exactly what they don't want, varies from kid to kid. One nephew hated car rides, so he pop his top at best buy, put him the the car and went for a 45 minute ride. He threatened to call mom, handed him my cell phone (he didn't have the balls to actually call mom). After 45 minutes of crying and wining (which works great on mom) he never crossed the line with me again.
With one of them telling him Uncle Vlad was mean worked like light switch with the tears.
The problem I have with spanking is every time I've seen it the parent is foaming at the mouth red with anger. The strikes aren't measured. Also I constantly see favoritism with spanking. One particular human prize would swat his daughter for every minor thing but his nasty little son could do no wrong.