There's always been certain kind of salesperson who thinks it's OK to "bend the rules" a little bit as long as they get to the result that they want. I thought of that the other day when I got an email with a subject line that included my company CEO's name and the word "important." As an attention grabber, that kind of thing works. But the content of the email had nothing to do with the CEO, and it wasn't important. Is it worth being clever if it also seems sleazy?

You see these tricks all the time, from the innocuous "RE:" inserted in subject lines to transparent lies about a new price list coming that will keep you from ever getting this good a quote again. Some of these are so common that they aren't even considered deceptive. They're just part of the game. But as salespeople get more aggressive with their bait-and-switch offers, gotcha clauses hidden in contracts, and promises of functionality that their product will never perform, they should be very concerned about the impact this will have on their overall success. Here are three reasons why credibility has become more important than ever for salespeople.

1. The shorter the interaction, the more it matters.

Everyone who's read about the Challenger Sale knows that buyers are showing up far more self-educated about the product. This means shorter sales cycles and less interaction with a salesperson before a deal is closed. At the same time, manufacturing a corporate facade is also easier than ever. With out-of-the-box websites and same-day setup for accepting online payments, anyone can put together a fairly credible front end to their business. All of a sudden, that short interaction with a human becomes the only real validation point to answer the question, "is this someone I want to do business with?" If a prospective buyer gets any signal that things aren't on the up-and-up, you simply won't have the time to rebuild your credibility.

2. Never have claims been easier to verify.

When a prospective vendor brags about their client list, I use LinkedIn to check references that they didn't give me. When a car shop tells me what a replacement part costs, I use my smartphone to check the price before I approve the work. There is nothing worse for a salesperson than to be caught making a statement that is verifiably untrue, and fact checking today can take as little as 30 seconds with Google.

Whether people are reading review sites while in the showroom, or posting questions in forums after the call, there is never a time when a salesperson will be the sole source of information on anything. In this environment, they need to be sure of their facts and able to back up their claims.

3. When there is a problem, you'll need the benefit of the doubt.

In any business of reasonable scale, there are going to be bumps in the road to delivering products and services. If only one in a thousand transactions has a problem, you could still end up having several problems a month, depending on how many customers you serve.

How customers react when problems come up depends on their relationship with you. If they trust you, then they'll work with you to resolve the issue. On the other hand, if they've seen some red flags, or if promises were made that can't be kept, they may look for revenge before resolution. Review sites are filled with scathing rants from people who think they were ripped off by one business or another. You want your customers to come to you before they go to social media, but they'll only do this if they believe in you.

Credibility has always been important for salespeople. What has changed so much is that buyers have unprecedented access to information and they are using this to verify what they're hearing from the people they're buying from. This change has fundamentally shifted how salespeople should see their roles, and what factors will make them successful. Those little sales tricks that used to be harmless ways to break the ice may have become the worst thing a salesperson can do to build long-term success.