Being on the receiving end of a juicy counter-offer is, for the emotionally needy, the fulfillment of a life's dream. It's like getting an email from that girl you adored in high school -- the one who didn't realize you existed -- saying she's been haunted by your memory these past 15 years and has remained completely chaste (but still hormonal) in anticipation of your reunion. Or maybe a slightly tipsy call from your ex-wife at 2:00 in the morning where she has to choke back the tears of remorse as she tells you that her new husband is a swine and she just can't erase you from her genetic code. Far be it for me to advise you not to accept a tasty dish of vindication. No excuses or apologies necessary -- the occasional gloat can do wonders for your health.
Surely by now you've heard all the standard reasons for being suspicious of an employer who doesn't pay you what you're worth until you give notice. But it might be interesting to freeze-frame the video on that exchange for a second and consider how easily you can be manipulated even though you think you're holding all the cards.
Let's examine your state of mind. You logged, say, five years of hard work and were hoping the payoff would have already appeared. When it didn't, you took a serious overture to its logical conclusion and earned the promotion somewhere else. Although you weren't actively looking, what's a motivated person supposed to do when opportunity knocks? Assume it's a burglar? And it's not just about the money, either. It's about recognition, respect, responsibility...the whole enchilada.
What you really want your boss to say is, "Thanks for the great work. I wish we'd shown you more appreciation while we had the chance. You've been terrific and we deserve to lose you. Wherever you go and whatever you do, I'm certain you'll be hugely successful." But instead he merely offers you more dough. And you're tempted to settle for that, minimally, as a substitute for what you really crave: acknowledgment. So in the radiant moment when your boss asks you to stay, as much as you might want to snort derisively and turn your back on him, you can't. It's like that hug your father never gave you. And now you have it. Sort of.
The most dangerous situation is not where you don't know what's going on and are therefore vulnerable. It's where you imagine that you do know what's going on but are dead wrong, because you're missing critical information or insight. We now understand this to be Dunning-Kruger effect.
Well, it's your decision. But please keep in view that you're highly susceptible to being played when you quit, and be aware of the reasons why. Also remember that the place where you pay your dues is often not the same place you'll reap the rewards for that work.