I recently accepted an offer with an organization and started this past week. Four days into it, another potential employer I'd interviewed with once (at the same time I interviewed for my new job) has asked me to talk with them a second time. While I like the job I just started (and the employer), I would love the other position more - it feels more closely aligned with my interests and values, and it is 20 miles closer to home. Both jobs pay the same salary. Any advice as to how to handle such a situation?
There are very few cases where I'd advise even considering taking a different job right after starting a new one, because doing so can harm your employer, your reputation, and even other job-seekers.
Let's start with the damage to your own reputation: Anyone who hears about this isn't going to rely on your word in these sorts of matters again; you'll be known as someone who cuts and runs. And people have a way of popping up again at other companies you may want to work for. Imagine that you really want a job offer in the future, and one of the decision-makers is someone who used to work for this employer. "Joe took a job with Acme but left for a different offer a week into the job" are not words you want spoken about you when you're interviewing.
Now let's talk about other job-seekers. Some of your fellow job searchers really wanted that job, but didn't get it because you gave your word that you'd take it. And it's not as easy as the company now going back to them, because some of them have since moved on to other things. (This is the same reason that it frustrates me when someone accepts an interview for a job they have no intention of ever accepting; that's an interview slot that could have gone to someone genuinely excited about the job but who got a rejection letter instead.)
And now, most controversially, let's talk about the impact on your employer. After you made a commitment to them, they took you at your word. They invested time and money in preparing for you and training you. They've planned work around the assumption that you'll be there. And they've turned loose their other candidates. They'll probably need to start the hiring process all over again with those back-up candidates gone, which means losing more time and more money, plus the opportunity cost of having the position open far longer.
At a large company, maybe this is easily absorbed. But I can tell you from seeing it firsthand that at smaller organizations, it causes real harm, so I strongly recommend factoring in the size of the organization.
The reason I called this controversial is that that I know there are a lot of people out there who say, "The company wouldn't hesitate to cut you loose if they needed to, so you don't owe them anything." The thing is, though, this isn't really true. The reverse of your situation happens all the time: An employer hires someone for a job and then, a few days later, a resume comes in from someone who looks even better qualified for that position. They don't (usually) rescind the job offer and say "sorry, someone better came along." They (usually) say "damn, maybe next time" or "I wonder how else I could use this late-breaking applicant." (There are exceptions to every rule, of course, and I don't doubt that some employer out there has handled this badly. But the majority don't.)
That said, it's true that companies make decisions based on their own best interests, and so it's reasonable that you should make decisions based on yours. But getting a reputation as someone who doesn't keep commitments and who leaves a job after a week isn't exactly in your interests. (Just as it's not in an employer's interests to get a reputation as a company that terminates people in anything other than a thoughtful, fair, and compassionate manner.)
Now, with that lecture behind us, there are a very limited number of situations where you can make a better case for what you're considering:
* The other job is your dream job, an opportunity you may never get again, and the first job is just something to pay the bills.
* You realized very quickly at the new job that there is something profoundly wrong with it -- the boss or culture is a nightmare, the job description is totally different from what you were told you'd be doing, etc.
* Your financial situation changed unexpectedly (family health crisis, spouse lost his/her job, etc.) and the other job pays dramatically more.
In these cases, it's easier to defend breaking your commitment, as long as you (a) fully explain the reason to the first employer, (b) apologize profusely and demonstrate that you know what a terrible situation this puts them in, and (c) realize that you're almost definitely burning that bridge.
But it doesn't sound like your situation fits this category: You like the job you just accepted. You knew what the job was and that you were getting a long commute when you accepted it. You knew it was possible that some of the other companies you'd applied to could still contact you, but when you accept a job, you are saying "I am going to stop considering other jobs for a while now." It's hard to make an ethical argument for backing out at this point.
I'm bracing myself for wild disagreement in the comments, though, so bring it on...