Imagine that your spouse of three years suddenly announces he's decided to "put the marriage up for review." He tells you that the relationship has been solid up until now, that you've performed above and beyond his expectations, but he'd still like to see "what else is out there."
You're flabbergasted. But, to his credit, he reads your non-verbals and tries to calm you down by adding, "Look, I've always thought it healthy to review my relationships every three years or so and, besides, the incumbent always has the advantage in these situations."
Hopefully, you've never encountered this scenario in your personal life. But, for agencies of all stripes, it's a way of life.
Usually, a review occurs after a new client management team moves into place. But, accounts can also go into review for no reason at all.
Every client has the prerogative to review his or her agency relationships. But, to do it "…every few years" is harmful to the momentum of the existing relationship. It's also a huge time suck and, even if the incumbent does somehow retain the account, things are never quite the same.
Agency reviews are like death and taxes. They're a certainty. And, as erstwhile NFL Coach Bum Phillips once said, "There are two types of coaches: dems that are fired and dems that are about to be fired." Ditto with agencies.
Oh, and just for the record, the incumbent never has the advantage in a review.