What happens to my host incentive if I have an annual subscription?

Edited

Host incentives are applied to the account on the next invoice. If you have an annual subscription, the total incentives will be applied all at once when it's time to renew your membership.

For example, you accumulated 10 months' incentives over your annual subscription, your next invoice will only be $200 ($20 * 10 months) instead of the usual annual fee of $400.