Selling a product that does not exist!
The story is quite long. In 1984, there was an Arabic/Egyptian movie. Its plot was about a director of advertising agency who is known for his skills in persuading clients. He was in some affairs with a belly dancer who wanted to appear in TV ads. He had to cry a lie, faked a filming location, & persuaded her that it's an ad for a new product. Product's name? He thoughtlessly answered, "Fankoosh" (a senseless word). After filming this unreal campaign, it was accidentally displayed as a real campaign. He had to invent any real product to fix this dilemma, and that was the movie plot.
By the time, the word "Fankoosh" was widely used by Egyptians in real life to refer to any unreal, exaggerated or overrated projects promoted by governments. What I'm looking for here is not the description of this thing, "Marketing a non released product" and so on. Rather, I'm looking for a common term or expression, or even a regional accident in English that delivers a similar idea. Thanks.