ALERT! The Club Nintendo year is ending with the month of June. That's about four weeks off.
If you have attained platinum or gold status, DO NOT ENTER MORE CODES. It's a waste. Enter those codes after your points for this year have been tabulated.
If you have not attained platinum or gold status, ENTER MORE CODES if you can to reach the status you desire.
Once the Club Nintendo year ends, enter any other codes you have and they will count for reward (platinum/gold) points once more. If you do it now and already have reward status, you're just wasting points that could go toward next year's reward.