In this research, we estimated the number of hits per song and its sampling error from 11 (areas including Gangnam) based on log data compiling the number of hits collected from offline karaoke players in March 2011. Then, we calculated the monetary equivalent of the sampling error under the current system that distribute royalties from the karaoke players to copyright holders(song writers and arrangers) according to the estimated hits. Because of the small sample size, the estimated number of hits had a very large sampling error. This research proposes a more reasonable sample design to estimate the usage of copyrighted music works for a fair distribution of royalties by reducing sampling error.