Preview Events are an event program available to WPN Premium stores. Taking place the week leading up to select Magic releases, these are effectively a one-week head start on Launch Party events. They use the same promo cards, and are run using the same formats: Booster Draft and Sealed. There is no limit to the number of these events you can run during the event window.
During Preview Events, associated product can only be used as event materials. Outright sales of the product must wait until the official release the following Friday.