The Wheel of fortune gives you a chance to win different rewards every day. You can generate new rewards for free a single time. Generating new rewards again will cost you 10 diamonds. After you spin the wheel, you can't generate new rewards before you claim the reward from the last spin. For each spin or respin you get 1 spin point; however, you can't accumulate more than 12 points in 1 day.
The daily free spin of the wheel of fortune will replace the reward of 1 diamond from answering a question in Polls.