Sales tactic is not dirogatory. Tactic : an action or strategy carefully planned to achieve a specific end. Hence, a sales tactic is a thought out approach on how to sell something. I would believe you thought how should I sell my knives, and you came to the conclusion that this method would work. It does work. It sells your knives from the sound of it in seconds. I do not have any direct experience in trying to attain one, but the board has many responses stating this fact.
I also believe it was neither your intent nor do you derive some kind of bizzare pleasure in having people glued to their screen to try and attain one of your knives. This is simply a testiment to two things: you must be making a very good knife that many people find value in, and those attaining them are willing to wait by their screen with preset typing etc to quickly snatch one up. This later point is borne once again from statements in this very thread.
Possibly a way to actualy reach a wider group of people who could someday attain one is to maintain a list. A very tried and true method of most every custom manufacture across the globe. It allows the largest audience to participate and it treats people in a more dignified manner. I am not implying nor stating that you are treating people with indignity. Rather, that by acknowledging that many people have carreers that preclude them from sitting at a screen at any time of their choosing, raises the level of dignity. The down side is it requires more work on your end. It requires the formation of policies etc. Also, significantly greater burden of communication. I do not know that his is the answer for you. But, I do know that your current sales (what ever word you wish to use) could be improved upon. Meanwhile, I am allowed to find the whole event a bit caotic and in that moment of caos humor.