Hole In My Shoe

I have a hole in my shoe. It's on the right heel of my favorite pair of flip flops. The left one is getting a hole too, but apparently I drag my right foot more than my left. The hole is about the size of a dime. I kind of like the little hole. To me, it shows that the shoes are loved. The question is...When should I throw them away? I don't want to throw them away, but at some point the hole is going to become too big. When? Maybe when it's the size of a 50 cent piece or maybe when it's the exact size of my heel? I guess I'll find out.