A recent Pew Research Center survey found that 87 percent of respondents believe it's vital to receive ongoing training and development opportunities. You can encourage this by having employees volunteer for new responsibilities so they can discover hidden talents and work on new tasks. You should also provide them with developmental support, like training opportunities and career mentoring to deepen their skills.

Another perk is that it keeps employees excited and engaged; it counters the apathy and boredom that can set in with long-held positions. A whopping 91 percent of Millennials have stated that career progression is a top priority, so investing in them can help boost retention over the long haul.