I previously worked at Microsoft. When I told my boss that I was leaving he asked a very polite question (I don't remember the exact wording) asking whether thi

I previously worked at Microsoft. When I told my boss that I was leaving he asked a very polite question (I don't remember the exact wording) asking whether this was open for negotiation, and I told him no, that I had signed an offer and intended to take it. We moved on to discussing how I would close out my existing work items. When a friend of mine (also at Microsoft) told his boss that he had a job offer from Google, but wasn't explicit about whether he had accepted it yet, they bent over backwards to try and persuade him to stay — offering, among other things, the promotion that he'd been passed over for in the previous two review cycles (so much for no promotion budget), pulling in upper management to spend time with him to persuade him to stay. All this just served to communicate to him how messed up his situation had been, if they can promote you now, why couldn't they before? As long as you have been clear with your management about your expectations w.r.t. pay/promotion/work etc. then any counteroffer is simply an open display of organizational misanthropy. w.r.t. Microsoft, one of the unspoken flaws in their review system is/was that by the time a review is delivered to an employee, it is too late to fix anything. If you think you deserved a promotion/bigger bonus/merit increase/whatever it has to wait until the next review cycle (a year) to be corrected (unless your manager is really prepared to fight hard for you and do things out of cycle—possible but hard)