Hmm. Pre-ordering. Reputable booksellers do offer pre-ordering on unreleased books from reputable publishers. And I believe the same is true for audio and video recordings.
Some years ago, I offered a batch of hand-made Christmas tree ornaments for sale, each one made-to-order. I required pre-ordering, so that I would have the individual specs and the total number of pieces to make, but I refused any attempts to pay for them before they were at least well-along in construction, in order to avoid having the product turn into vaporware.
And I also made the plans and instructions freely available on my web site.