I ALWAYS spin the tire after applying the weights. Only rarely do they need any additional attention. As often as not, they just need one of the weights moved a small amount rather than more weights added.
But it is obvious that some tire shops do give the tires a check spin. There are multiple weights in several places around the rim. 
Seeing that will always make me laugh out loud. Especially when it's a high-dollar car like a Camaro that somebody has put WAY too much money into but there's a Kraco cassette player hacked into the dash and at least two wheels with multiple weights.
Or when you see a wheel with a weight PAINTED to match the wheel, but then fresh lead weights on another location.
Bless their hearts.
