How did that deal go down?
1. The individual has to be open to hearing the offer at all. Jack was bored, disillusioned and aimlessly walking to market. Sure, it was a shady guy on the street, but Jack's standards were low. If you want to do business with people with more resources than Jack, it helps to have the trust that comes from previous engagements, and the permission to deliver your message.
Most of all, Jack was in the mood to buy. Creating a mood is far more difficult than finding one.
2. The person hearing your story has to want to believe it. This is more subtle than it sounds. Uber, for example, offers a newfangled way to call for transport in big cities. Many people haven't heard of it or used it, largely because they don't think they need it, aren't open to something new, or are unwilling to go through all the steps necessary to get the app, etc. So, even if it works as promised, there's no urgent need felt by some, so they don't care.
In Jack's case, the prospect of escaping his dreary life (and getting rid of the pesky cow) were both welcome offers. He hoped they'd be true.
3. It has to be true. You must be able to keep the promise. If not, you're ripping people off and shortcircuiting any chance you have to build something of value. If the beans hadn't grown, end of story. Future sales will come when Jack tells his friends...
Marketing failure occurs because at least one of these three elements isn't present.