Remember the “good old days” of selling -- when vendors controlled the flow of information and buyers were compelled to interact with them to leverage that knowledge? Studies have described the reality of today’s selling environment: Business-to-business sellers are becoming involved in buying cycles late in the game because customers are doing their own research.

Despite the changing landscape of buying behavior, however, most vendors and their salespeople cling to old habits, which were annoying 10 years ago and are downright offensive today. The chasm between the way buyers want to be treated and selling behavior is widening.

Buyers inherently mistrust salespeople. Who has not had an unpleasant experience with a seller who selectively parsed product information in a self-serving fashion? It comes as no surprise that customers want to reduce or eliminate a seller's ability to influence his or her requirements.

It’s high time that sales teams catch up and revise how they approach buyers.

Related: Evolve or Die in the Age of the Consumer

In the past when new offerings were announced, buyers had no choice but to tolerate contact wit salespeople. With the motive of generating higher revenue, vendors posted massive volumes of information online in the late 1990s, inadvertently ceding a significant amount of control.

Starting about a decade ago, social-networking platforms for business -- most notably on LinkedIn -- introduced much needed transparency to beleaguered buyers, allowing for third-party comments and reviews. Since then, buyers have become empowered. Today, do-it-yourself or DIY education has become commonplace.

The old saying was that happy clients would tell four people while unhappy clients would tell 13. Now with the Internet and social networking, multiply those numbers by thousands. While company websites might make claims of high-quality, satisfied customers, reliability and ease of use, buyers can solicit firsthand impressions about business products and offerings from people they know and trust. Seller or vendor claims can be verified before being accepted. Buyers are no longer susceptible to false or misleading claims made by vendors.

Knowledge is power. Buyers have leveled the playing field.

Related: Market Research Has Lost Its Mojo. But Here's How It Can Get It Back.

It’s unclear whether vendors view changes in buying behavior as the elephant in the room (not to be discussed) or are aware of the shift but have concluded nothing can be done. I see few enterprise-wide best-practice responses from vendors. Each seller decides how to best interact and align with knowledgeable buyers. By failing to act, vendors' claims of being customer-centric ring hollow.

Long-term inaction increases the risk that sellers will become irrelevant. Most sales methodologies and individual approaches view buyers as blank canvases when it comes to their needs. That’s a dangerous assumption to make about potential customers who may have already done extensive research via the Internet. Sirius Decisions has found that customers go through as much as 67 percent of their buying process by digital means.

When contacted, most traditional sellers either never discover buyers' requirements or make premature attempts to change them. These actions disrespect buyers' research and reinforce their decisions to avoid sellers because they don’t listen and are manipulative.

It’s time for vendors to realize the following: 

A seller’s primary role is not to educate prospects from scratch. The executives in the crowd who may be buying don’t have the time. Others don’t want to deal with salespeople and opt for self-education. Today’s reality is that marketing, historically the back end of the product-development process, must become the front end of the sales process.

Inbound sales leads can be lower-level, nondecision makers who have been tasked with gathering information. Salespeople need to have a proactive plan of how they will leverage that interest into attracting engagement by executives.

Sellers can help executives and those in lower-level positions by introducing business issues and value into product evaluations. By first understanding and aligning themselves with the desired business outcomes of a buyer and then introducing potentially new insights into a discussion, sellers can marshal their approach to be a competitive differentiator.

Establishing potentially unique value early on is in the mutual interest of buyers and sellers. If there's insufficient payback for a product, a buying decision is unlikely. 

Top-line revenue is the lifeblood of organizations. Significant upside exists for vendors who align all aspects of their selling machine with buying behavior. Superior buying experiences can become a sustainable competitive advantage. 

Related: Why Crowdsourcing Is the Answer to Business-Software Reviews