Originally Posted by Furball

This all hinges on just how much money the deposit ends up being. It's just like the deposit you give your landlord when you rent a home, to remind you there's something at stake in it if you mess the place up when you move out, they'll withhold the deposit and put it towards fixing up the mess you made. It's implimented in the real world, so I can understand why it seems to be a logical way to give players an incentive to behave.
The way I look at this is that if the deposit is small, more people can easily pay it and enjoy the server, but the stake will be small enough that a rulebreaker won't care if they lose it. On the flip-side, if it's too big, exponentially fewer people will be willing to pay it and the community suffers as a result. With premium being a monthly cost, it will serve much better as a deterrent to breaking rules because the money was effectively invested into those characters and would be lost if they got themselves banned.
I don't see deposits working on products that are not a necessity in people's lives as housing is, but I'm also by no means an expert in the financial field. I'd personally pay it as long as it's around the $5 area, but any more than that and I'd be thinking twice about whether it'd be worth the hassle. I have no desire to break any rules and gladly pay for premium in order to get the most out of my gameplay for the time that I can enjoy it.