The Insurance Policy is a sale that provides half the Coins upfront, and then the other half if you lose the Coins within 24 hours.

For example, if you purchase a sale for 500,000,000 Coins + extra Coins, you will receive 500,000,000 immediately after the purchase. Then, if you lose all of those Coins within 24 hours, you will receive the other 750,000,000 Coins. In this case, a losing spin is defined as one where your bet was larger than any payout.

When you have lost all the Coins, exit the machine to the slot selection screen. You will then get a popup with the other half of the policy.