When you get a job offer it's better to take it than to accept your current firm's counter-offer, according to Bruce Allen of Rutan & Tucker. In a recent Marketing Catalyst blog post he says, "An amazing statistic is that 89% of people accepting counter offers are gone in 6 months. 89 PERCENT!"
He recounts how me made a job offer to a woman to join his marketing team. "When partners at the last firm found out she intended to leave they pulled out all the stops; made promises; told her everything is going to be great from here on out. She stayed." Bruce wrote.
"Not too many days later I've heard from her and now she is MEGA unhappy. The partners may have wanted things to transform, but the people she actually reports to are still the same." he says. "If the relationship is not transformed, money and platitudes will not change a thing. A huge discount (or a raise in the case of my teammate) changes nothing about why someone is unhappy."
So maybe the grass is greener on the other side. If you get a good job offer, simply take it.