What creates sales success? Some people say it's personality; successful salespeople are outgoing and friendly. Some people say it's expertise; successful salespeople understand problems and find solutions.

While those things are no doubt important, I've met successful salespeople who are quiet and introverted. I've also met successful salespeople who can develop opportunities even when they barely know their product.

In my view, every great salesperson intuitively understands these two deceptively simple rules:

1. People want and need to be heard.

Most people in business (including high-powered decision-makers) feel as if they're buffeted by forces beyond their control, like the economy, technology, stock prices, the government, and so forth.

People feel especially powerless when they think nobody is hearing what they have to say. By contrast, people feel powerful and in control when they're certain that somebody is listening to them.

Great salespeople are always great listeners. They know that when prospect and customers are happiest when they're talking to somebody who's taking them seriously, really listening to what they've got to contribute.

2. Don't provide information unless asked.

We live in an age of massive information overload. Today's business challenge is to focus on what's important and filtering out what's not. That's why people get so upset and frustrated when they're forced to see or hear information against their will.

Marketing and sales techniques that attempt to force information down people's throats--like robocalls and intrusive advertising--create hostility. By contrast, people are delighted when they get the exact information that they've asked for.

Great salespeople always ask permission before they provide anything more than a brief introduction. They never launch into a sales pitch or hand out brochures to all and sundry. They wait until asked because then they're sure the information will be welcome.