Employees are vastly more satisfied and productive, it turns out, when four of their core needs are met: physical, through opportunities to regularly renew and recharge at work; emotional, by feeling valued and appreciated for their contributions; mental, when they have the opportunity to focus in an absorbed way on their most important tasks and define when and where they get their work done; and spiritual, by doing more of what they do best and enjoy most, and by feeling connected to a higher purpose at work.
This was in the Times last Sunday and is an awesome summary of how to think about motivating and retaining great employees. It highlights simple but critical points like taking breaks to avoid burnout, helping employees gain a feeling of mastery by providing specific and customized challenges, and maintaining a constant feedback loop.