They're "the new rainmakers" for your company. They're needed everywhere - in the office teaching peers and in the field doing the work. Attracting and retaining them is "essential" to your organization's success.This is what experts are saying about today's subject matter experts (SMEs).But the landscape is changing quickly. Now there's a new way for companies to discover the SMEs in their midst. One financial industry giant is even celebrating the fact that the old determinations for SMEs are gone.To understand today's SMEs, their role in talent development, and the keys to retaining them, you need to start with what the term really means.What is an SME?A subject matter expert is a "person with bona fide expert knowledge about what it takes to do a particular job," as the U.S. government defines it."SMEs are extremely important to organizations today," says Sarah Wakefield, training manager for the energy company Schlumberger. She facilitates a course on SMEs for the Association for Talent Development (ATD). "With the pace of change, sometimes SMEs are the only people who hold answers that others in the organization need."SMEs must not only know a topic or skill inside and out, but they also must "know the context for it" inside an organization, says Allison Rossett, a learning and technology consultant and member of Training magazine's HRD Hall of Fame. "If you are a subject matter expert, then presumably you know information that is useful today and tomorrow" in applying that knowledge to the specific field you're working in, she says.Who decides which employees are SMEs?Traditionally, organizations have used a top-down approach. Executives have selected employees to serve as SMEs, having them do some teaching and training as part of their responsibilities.But today's successful businesses are starting to follow a new model. They're working to build an agile workforce in which employees are constantly learning new skills and sharing knowledge with each other. This means that anyone, at any time, can develop or highlight expertise.That's one reason Visa had founded Visa University, centered on a "digital campus."Using Pathgather's talent development platform, Visa University has transformed the company's Learning & Development. A key feature is that it allows any employee to add content or create a course."The whole concept of social learning is peer to peer," says Matt Peters, Visa's director of technical learning and development. No one is specifically named by the company as an SME, but anyone can effectively act as one.One net result of this new model is that companies are discovering experts they didn't know they had. As emerging technologies make new skills necessary, companies can turn to their talent development platforms to find out which employees have expertise in those skills.A new way to 'package' SMEsAlso because of new technology, experts no longer need to be inside classrooms. Their courses and videos make them accessible to learners at any time."They're gaining importance," Rossett says. "And now businesses have much more technology to package them."The question becomes how best to capture "the essence" of what they have to teach without overloading learners. It's about extracting "the eau de SMEness," Rossett quips.Some SMEs resist documenting their specialized knowledge, Wakefield says. "They perhaps see it as losing their job security or their SME status. However, this is not the case. By documenting, recording and sharing their knowledge, they are becoming even more important." A top business trendEach year Ian Altman, a business sales and growth expert and Forbes columnist, lists the "top business trends that leading companies embrace to drive success." For 2017, he predicted that the top trend would be subject matter experts becoming "the new rainmakers."Pathgather reached out to Altman to ask him whether that prediction panned out. "Absolutely," he responded. "Some businesses are growing at extraordinary rates by engaging and empowering SMEs."Altman focuses especially on B2B sales, and says businesses would much rather buy from a subject matter expert than a typical salesperson. "The best organizations surround SMEs with support staff" who help them navigate the process, Altman said.How to attract and retain SMEsSome consultants have spent years calling on organizations to make efforts to hold onto their SMEs.Doing so is "essential to the organization's success," Andy Jones, Gerald L. Kovacich and Perry Luzwick wrote in their 2002 book Global Information Warfare: How Businesses, Governments, and Others Achieve Objectives and Attain Competitive Advantages. Compensating SMEs "is cheaper than loss of productivity, training costs and customer ill will," they wrote.But the keys to retaining SMEs aren't always financial.One strategy is to "make a hero of them" by singing their praises, Rossett says. And some companies add "subject matter expert" to the person's title or job description, giving them stature and a stronger resume.Rossett has seen some companies create online social networks for SMEs to interact with each other, and even "hold events and send them gifts." Some SMEs have been given iPads. Others were taken on trips and getaways. "Basically, the company was saying: 'We value you.'""There's a zillion things you can do, but you've got to think about it. And it will vary based on the corporate culture," Rossett adds.Says Wakefield: "Wow them with success stories of other SMEs who have shared their knowledge and went on to do other great things."Altman suggests businesses should take a few key steps to hold onto SMEs: make clear to SMEs that their work serves an important goal; surround them with the right culture that makes them want to stay, and invest in their professional development. "When you do that and provide them with some level of autonomy, that's the sort of place they'll want to work at today, tomorrow, and next year," he says.But if a business mostly ignores SMEs, "they're probably not going to want to stick around."The good news is that most of these experts "actually realize that they play an instrumental role in helping their businesses grow, and they want to keep doing it," Altman says, and the more they internalize that, the more they feel involved and become "active, enthusiastic participants."