The biggest mistake in sales
Actually there are tons of mistakes you could do in sales. But if I should pinpoint one thing, this has to be it:
You argue with your clients
You should ever never argue with your clients. Let me repeat that: NEVER argue with your clients. Nothing irritates me more when I observe other salespeople having an demonstration with a possible prospect, and they start an argument telling the client that they are wrong in certain ways.
Selling is all about agreement and building rapport, and by telling the other person that they are wrong, you are simply saying that they are stupid! Would you buy something from a salesperson who calls you stupid? Certainly not, and the same goes for any other human being on the face of this planet!