$3k or even $10k (as another commenter suggested) to bail out on a company that you just started at, is a way of making the people who really don't like the company not feel bad about leaving. Even at great companies, there are people who join who hate the environment, culture, or whatever. They are miserable. But they stay because they need a job. The walking money of $3k is a matter of getting rid of them, which is a great investment for the company.
For people who like a company, or who really want the job, a quick $3k isn't worthwhile. And in the case of Zappos, I'm sure that they've generally had people stay longer, lower attrition rate, etc., primarily because they've gotten rid of the people who would generally be a drag on the company, because they've already bought them out.
For people who like a company, or who really want the job, a quick $3k isn't worthwhile. And in the case of Zappos, I'm sure that they've generally had people stay longer, lower attrition rate, etc., primarily because they've gotten rid of the people who would generally be a drag on the company, because they've already bought them out.