What makes Montresor's entrapment scheme successful?

Montresor's scheme to lure Fortunato to his death may be understood from the few lines of dialogue between the two men when they first meet. The following is what Montresor says, with Fortunato's dialogue left out.
I said to him—“My dear Fortunato, you are luckily met. How remarkably well you are looking to-day. But I have received a pipe of what passes for Amontillado, and I have my doubts....I have my doubts,” I replied; “and I was silly enough to pay the full Amontillado price without consulting you in the matter. You were not to be found, and I was fearful of losing a bargain....I have my doubts. And I must satisfy them. As you are engaged, I am on my way to Luchesi. If any one has a critical turn it is he. He will tell me—”
Montresor has honed his story to perfection. He wants to get Fortunato to come to his palazzo immediately. Otherwise Fortunato might have time to check on the story and find there was no newly arrived shipment of Amontillado in port. Fortunato might also tell other people that he was going to Montresor's home at his request to sample some wine. But Montresor's story forces Fortunato to come immediately if he wants to come at all. Montresor says he is on his way to see Luchesi. He pretends to be in a big hurry to have an expert sample his totally fictitious cask of wine and tell him whether or not it is genuine Amontillado. Why? Because he got it at a bargain price. He only bought one cask because he wasn't sure it was genuine. But he would like to buy more if he can get an expert to taste it and reassure him.