As a supervisor, team leader, or co-worker, it's important to observe an employee's past behavior before labeling them as "unmotivated" or "lazy." There may be a legitimate reason an employee is not performing up to par.
There's surprisingly little rigorous evidence demonstrating that companies really can make money by doing more good. To this end, my collaborators and I have spent time over the last several years carefully document the positive impact of kinder, gentler corporate initiatives.
There is no better motivator than appreciation. Often, by simply showing your appreciation for someone's hard work, drive, enthusiasm or work ethic, your acknowledgment encourages more of the positive behavior you are seeking.