Cloud pricing is subscription based. You are eligible for automatic version updates as long as your subscription is active. When your subscription renews each month, you are automatically billed for host products and apps based on the number of users in your instance. If app pricing changes after your initial purchase, there's a 60-day grandfathering period during which you can renew based on the old pricing.
Academic, community and open source licenses are not available for cloud apps.
For cloud apps, you cannot extend your free evaluation period. All cloud apps are immediately subscribed by a user, and we provide a free evaluation period. This is a minimum of 7 days and ends on the second billing cycle after you first subscribe to the app.