Turf Boss is a relatively simple event that runs from time to time. When the event is active (an icon will appear on screen) each completed territory will grant you increased rewards. In addition to 25 spins, you will also receive coins and at least one Revenge (which can be used later).
The event is automatically applied to the account, so if you do not click on 'Let's Go!' you will still receive the benefits if you complete a territory in-game.