Pre-order...
Simply, prior to the initial run/release of a product/effect, PM offers enthusiastic purchasers the ability to pre-order the trick so that they are one of the first to receive the effect once it's being delivered from online sales
Based on different metrics to judge popularity e.g. forum interest, convention sales, yada yada yada, not all items are available to purchase early.
The benefits to the parent company are obvious.
Candidly, , in my opinion, rarely do they meet the hype
However, if you find a 'must have' for your collection, pre-order offers you an avenue to receive one of the first units once they become available to ship.
Have I ever taken 'advantage' of pre-order?
Certainly, but, as mentioned, it is rare.
The last product ordered by me...early...was 'Little Door'.
A great trick (I ordered 4 units) and PM is still having a difficult time meeting demand and it's been over a year since introduction.
Sometimes PM will offer pre-order on the 2nd run for the product (rarely).
Secondarily, most likely, the product will just show 'out of stock' on the product page and everyone waits for restocking...
The pre-order process is the same as a regular order. One thing to note, if you order other items that are 'in stock' and available, PM will hold your total order until it can be shipped complete with your 'pre-order' item included i.e no partial order fulfillment. That's why ordering a pre-order item separately from other tricks/supplies should be considered.
Best wishes...