The insights on R&R policy are extensively given above. However, do remember that an exclusive policy for R&R will entail costs, measurement criteria to be well communicated, continuous discipline of announcing on TIME the names and the reasons in a logical manner.
Also, many times, though a person is given R&R, he or she may have only indirectly contributed and his team may have given extra efforts/time. In such cases, dissatisfaction can also creep in, and the productivity/confidence will go down in the implementation of such a policy.
Overall, today's employee is more of an immediate benefit seeker than a long-term 1-year to 10-year reward. He/she wants to be acknowledged at the earliest instance of something good done by them. Therefore, sometimes, a fixed monthly/weekly, etc., type of policy may also demotivate a person to a small extent.
However, R&R helps build the company's workforce to create better productivity/cost reduction, etc., and improve the bottom line. So in many cases if the impact of someone's good work is translatable into MONEY, it would be worthwhile to show that impact on the annual bottom line.