While emotions might help you build the trust and the engagement you desire, too much of it might make a listener think that you are too emotional to take a tough decision or a level-headed discussion.
They might also think that you are riding on emotion alone for the success of your business, hence always back everything you are saying with facts and figures that prove what you are saying by providing a precedence.
Two skills are involved in introducing facts in a conversation in a manner that appears suitable and in accordance to what the listener is expecting to hear. One of them is separating the facts from opinion. At this stage of the discussion, people should be able to understand which statements can be proved and backed by facts, and which statements are only the thoughts of others.
After that, the second (and more important) skill is to use the facts to enhance the presentation of your argument and to support your decision. When this is done, the listener will have no other option but to appreciate what you are saying as you are not only using facts but also giving a logical thread of explanation that connects and relates all of them.
At this point, there is always a risk of the person feeling intellectually threatened, so back off a little and ask him for his opinion. Always keep the listener involved in a conversation.