At almost every established company, there are employees who have been around for such a long time and are so good at their jobs that everyone else has a hard time imagining the business functioning without them. They know every client, or they're expert at getting things done, or when a problem comes up that no one else knows how to solve, they can remember a solution that worked once, a long time ago, and will do the trick now. For that reason, some may be quite happy in their current positions and not looking for promotions. In many ways, they are your "star performers" and their deep knowledge of the company is invaluable, and often, irreplaceable.
It's often thanks to that reservoir of experience that a company can find exciting new applications for great ideas from the past. Sometimes, your most experienced people may suggest a look backward rather than something new, but this can be very useful: A lot of supposedly new ideas are nothing more than recycled old ones.
When we at Virgin started up our very first record store in the 1970s, we tried to create a hangout atmosphere, with free coffee and cushions and beanbags for our mostly teenage customers, hoping that if they relaxed and talked about music, they might be more inclined to buy a record or two. It was nearly a revolutionary concept at the time, and our much larger competitors dismissed us as a bunch of crazy kids who didn't understand the business.