At first, they will tell you that they are a candy factory. They will give you the sweetest word that everyone wants and it is to have some bitcoins without doing any work , you just need to wait.
Yeah wait, it's pretty cool and simple, huh? After taking the first bite of their candy, you will be overwhelmed that it was so sweet that it let you feel the urge to buy again. Well, as usual being a person eaten with greed, you'll blindly bite again. You may also reach to the point where you'll refer them to your friends and family, may invest and so forth.
In the end, it will all be bitter nothing else. No bitcoins, no sweets.
Nice analogy, but most of the time I think of these scams as bait and switch, basically they offer you certain things and at the end you get nothing, this is something that happens everywhere, I remember that I saw once an ad on TV about very cheap televisions, many people went there to get them but it turned out that all the TVs were sold already, but do not worry they were willing to sell you other TVs for an outrageous price.