Now, the bad side.
If you're over 18, like I said - you WILL get a lot of hours. Unfortunately, they will all be closing shifts and it is highly likely you will be working them alone. Most shifts will be during prime social hours, so say goodbye to your social life and don't expect anyone to ever give you a weekend off - even if it's something important like a wedding, birthday, etc.
Communication SUCKS. If you have an issue that can't be handled instantly, you'll be told to use Workbrain to talk to whomever - even if you're talking to that person face-to-face right then and there. Do not expect a response, and do not expect whatever you asked for to get done.
Most of your co-workers will be 16-20. Although many of them will be friendly/likable/potential friends, expect a lot of egotistical teenagers, cry babies, and emotionally stunted jerks. Most of them you can handle/ignore, but you'll get a few who have kissed up to the managers and are NOT afraid to lie/tattle to get their way.
Pay is minimum wage (expected) and alright for the minimal amount of work you'll actually do. However, you'll always be working weekends and you will always be working late (if you're over 18). You will also work holidays.
The managers have all worked there for years. Other than that, expect a few people who have worked there 1-2 years. Everyone else will be as new or newer than you and they will not stick around. Late-August through early November there will be a surplus of new people, only for them to quit for the holidays and rejoin in early January... so they can quit again in June.
Customers are usually alright (75%+ of them want popcorn, a drink, and to be gone), but you won't remember them. You'll remember the one-in-a-hundred customer who was great, and the unfortunately overly common problem customer. Expect kids who open up bags of candy before/without paying, soccer moms who have specific (and ridiculous) requests that they'll snap out at you and conartists who will try and get free food. On a lesser scale, expect customers who will go and spill 90% of their popcorn and say you didn't fill up the bag, or ones that will claim something is cold/bad but refuse to return it (while demanding a new one).
Oh, and it's going to all be "your" fault.
Kissing up is the only way to go anywhere, but you may not want to go anywhere. Managers do all the work you do, and then some; the only perk is they (to some degree) get to decide where they're working that day, while you generally don't. Pay isn't much more unless you climb to the top of the ladder, which can take 20+ years and isn't a promise then.
No health benefits.
You will be expected to up sell (easy), but also to sell stubbs cards (purely luck based). Even if you're the friendliest, fastest concession worker and you manage to up sell every drink, popcorn, etc. you'll be considered "lesser" than the guy who sold four more stubbs cards than you did. If one of you gets fired, it'll be you; not him.
