Talking too much. One of the oldest Sandler philosophies is the 70/30 rule. So often and especially in the beginning of a relationship, salespeople think they need to be doing all the talking, when they should be listening and asking questions. Keep in mind, if a prospect wanted a rundown of your products or services, he or she could just visit your website. The sales process is a conversation, and an honest and open one at that. (Sandler Rule #14)