I listened to Carlton Palmer's Under the Cosh podcast recently.
He was talking about 'staying up' bonuses at Southampton under David Jones. As soon as they survived, the players took their foot off the gas.
Palmer had a bonus incase they ever got into Europe, but not the survival bonus. Unlikely, but he was focused on the challenging targets not just the bare minimum.
So these incentives can help you meet your minimum aim, but are costly and counter productive at times.