Here are my thoughts, and I speak as having been an assistant manager for a dollar store for a year and a half (Sept 2008 to April 2010). Let me disclose out of fairness that I work in storefront retail - the absolute WORST-paid profession there is, and that the whole of my experience/frame of reference is viewed through that particular prism. And I worked under a wonderful store manager who felt - and still feels - the same way I do on this subject.
What I used to tell the new cashiers I used to work with, when I first met them, is that: "First, welcome aboard, and we're glad to have you. But Second, I'm letting you know now, that from years of experience, I know that storefront retail is, like, the worst-paid profession out there."
"I understand that the whole point of working is to have $$$ enough to pay the bills, take care of your living expenses, and have enough $$$ to just enjoy life, in general. With that said, if you find another job anywhere else that pays you better than what we could pay you...by all means, go for it. Cause, if you don't, I will.

We don't care if you take that better-paying job, and you just started here. All we ask, all we expect from you, all we want from you...is for you to just be straight up with us, and come and tell us that you got a better-paying job."
"Lord knows, times are hard enough for everybody - that's not news. But if, at anytime, you find a better job, just be honest with us that you're leaving, and why you're leaving. We will smile, give you a hug, and wish you well."
As a former boss, I would have 1,000,000,000,000,000 times more respect for a new hire who came and told me that he/she had found a better job than what we could pay them, and told me, "Look, there's a better opportunity over there than there is here". My old store manager and I have ZERO respect for someone who just quits out of the clear blue - no notice, no-call/no-show, no nothing. Even if you wanted to quit *this afternoon*, and I just hired you *yesterday*, all I ask of anybody who would work for me is that they be a person of character and come talk to me, first. I won't bite, I promise!
I remember this one girl who worked for us for a week and a half. We instantly clicked with her, and she was great with the customers. Later that week, one of her applications she had sent out was for a new supermarket that was going up closer to where she lived. She had told us that they wanted to make her an hourly supervisor over the front checkouts (ie. more $$$). While we didn't like losing her, there was nothing we could do at store-level about increasing her starting pay rate. And we were happy for her that she'd found something better. Her last day with us was the Tuesday of the next week. My boss, the other assistant manager and I went in equal on a $30 gift card to Denny's.
Be a person of character: Even if you wanted to quit *today*, just be honest about it.
Hope that helps.
Thanks!
