It's similar to an engagement proposal for marriage. You aren't legally requiredto get married if you get engaged --- but having an engagement first gets all pa

It's similar to an engagement proposal for marriage. You aren't legally requiredto get married if you get engaged --- but having an engagement first gets all parties more committed, makes it clear that there will be a next step. He mentions in the article, it serves to provide some sort of verifiable agreement on the important numbers, and security that the buyer is serious