Though I cannot find them now, there have been studies done that I seem to recall showed pretty conconclusively that paper towels are much more sanitary than air dryers. There was even an old Myth Busters episode on this exact topic:

Hand dryers or Paper Towel? That is the question.How many times have you washed your hands in a public bathroom and searched in vain for a paper towel dispenser? Who wants to wait around while some electronic gizmo on the wall blows lukewarm air on your clammy hands.www.mcgill.ca

The air dryer blows whatever is on your hands all over the place!

Typical cheap choice-Electric hand driers create "impression" you care about your customers. When I travel I learn which places have cleanest restrooms and good supply of paper hand towels. Always tip rest room attendants , tho harder to do today as we frequently don't carry cash. Was fascinated to see much cashless pay on smart phone apps when in Africa. Surprised I don't need an APP to use the electric hand driers. Progress:>(

As I think of it, the very nicest restaraunt's restrooms always have clean cloth towels to use, or nice paper towels..