Have you ever played the game of telephone? In this game, a group of people form a line. The first person in line whispers a short message to the second person in line, who then tries to repeat it to the the third person in line (by whispering it), and so on. The game ends when the last person in line receives the message and then the first and last person announce it to everyone. The group will often break out in laughter when they realize how distorted the message has become as it traveled from one person to another.
If the participants in a game of telephone can't even repeat a message verbatim after it is communicated to them, imagine the misinterpretations that arise when technical people try to communicate with non-technical, business people. These two groups of people really seem to speak a different language and have different motivations, which affects their communication style.
How do organizations deal with the incompatibility among these two groups? Take the example of Justin, a sales rep. working at a hypothetical enterprise-software company. Justin has an expansive network of contacts and excels at prospecting for new business, building and maintaining customer relationships, and closing deals. Justin, not being a technical person, understands the features and benefits of the products that his company sells, but not how the products work "under the hood". Because the products that he sells are complex, prospective customers will often have technical questions/objections that need to be overcome before a sale can be made. Also, prospective customers will often want to see a demo before committing to a purchase.
At first, Justin would direct all technical inquiries and demo requests to the Engineering department. But Engineering was very busy developing software, and found it distracting and overwhelming to engineer products and provide sales support at the same time. So, Engineering wrote a list of Frequently Asked Questions (FAQ), and also developed a generic sales demo and provided these materials to Justin. Justin was very appreciative of this effort, and relied on the engineers to a much smaller degree. But, then another problem arose: Because the engineers were no longer involved in the sales process, Justin would often make assumptions about the answers to technical questions when they weren't on or not fully explained on the FAQ. Also, many prospective customers would request custom demos prior to commiting to a purchase, so the generic demo provided by Engineering really wasn't adequate.
It seemed that whether the Engineering department was involved or not involved in the Sales process, the organization could not deliver sales support effectively. So what did the organization do? It created a Sales Engineer position that was filled by Mary, a technically skilled person who has also shown a great interest in interfacing with customers. Mary works at the intersection of Engineering and Sales. She participates on customer calls with Justin on almost a daily basis. She knows the product very well "under-the-hood" and can address the majority of technical inquiries. Mary also spends some of her time coding custom demos that have been requested by prospective customers.
From a technical standpoint, does Mary know the company's products as well as the engineers who develop them everyday? No. From a customer-facing standpoint, does Mary have the same level of finesse and poise as Justin? No. But Mary possesses both of these things in sufficient amounts, surely resulting in better value-add to the organization than would be realized in the absence of the Sales Engineer position.