Blackmail: force (someone) to do something by using threats or manipulating their feelings.
As in 'emotional blackmail'.
Perhaps you were thinking of the other meaning?
The practice is based on manipulating the emotions of the would-be customer. If you care that much about the product. If you don't pre-order you don't get the bonus, right? It is manufactured scarcity intended to create a fear of loss.
Sure, folks might say it is 'rewarding the customer' - but you can do that without the cheap - though proven effective - psychological tricks.
Perhaps, ''attempted blackmail/emotional blackmail' would be more accurate, because they haven't successfully 'forced' anyone to do anything. Rather, they're attempting to through scarcity and the fear of loss.
Unless anyone honestly believes such practices are done out of the kindness of WOC's heart? I'm sure some folks do!