I purchased multiple pairs of these in case the flip flop strap ever broke.  Thankfully it hasn't, but I keep a pair at work and one at home.  In time, it does loosen a bit, but I blame it on wear and tear.  I don't know how many times someone has stepped on the back of it and I was sure the strap would come off, but it didn't...it's now just a bit loose.

Shoe is perfect for everyday summer wear, the beach and if you want to look a step above casual beachwear.  I like to wear it w/ summer dresses.