Bate And Switch
Bate and Switch is a simple advertising technique whereby the advertiser advertises one thing the bait, you the prey, strike. But upon arriving at the sales location, you cannot find the bait because it has been switched to what the advertiser actually wanted to sell. " Sold out, but we've got something just as good and maybe better". Presumably the advertisers suspects that you would not have come in had he advertised what he actually wanted to sell or at least not as many prey.
To circumvent laws passed prohibiting such activity, advertisers would have one or two for sale and then they could legitimately say it was sold out.
With the Internet it is even easier. It is not even necessary to advertise directly, just veiled promises and talk. You're interested, you strike click. Upon arriving you find a plethora fascinating things, activities, and more veiled promises.
It is very likely you will click on one of those for one of at least four reasons. Now it is more interesting than what you came for; You think it is what you came for; You've forgotten what you came for; or You've given up.