The difference between buying a bag of pretzels and buying a tampon from a vending machine

Buying Pretzels:
You can see whether or not there are bags of pretzels available before putting your money in the machine. You put in your money, and 9 times out of 10, you get pretzels. Excellent, now you have a quarter to go buy a tampon, and pretzels you didn't really want.

Buying a Tampon:
You have no idea whether or not there will be any tampons or pads available for purchase because the metal box is entirely opaque. You just have to put your quarter in and hope for the best. 9 times out of 10, you get nothing. You jiggle the handle, pull at the sides of the box, and jam your hand up into the machine. Your hand is stuck. This looks bad. Okay, hand is free again, time for the reinforcements. You jam a pen, ruler, plastic knife, whatever longish item you have at your disposal smaller than your hand, stab at whatever is up in the machine, hoping for the best. More prying at the side of the box, and if you're lucky, its not locked top and bottom and you can reach in and mess with some levers. Still no luck. More jabbing with your makeshift tampon stealing tools, leaning over, sad staring into the machine, etc. If you're me, it takes you a long time to give up because you put your quarter in and you WILL CLAIM VICTORY over the machine. Sometimes it works out, and sometimes you end up sitting on a preposterous quantity of toilet paper stuffed into your underwear.