Usage of K-means clustering
The K-means algorithm usually compares well to more refined and computationally expensive clustering algorithms concerning the quality of results.
The range of possible values of the k parameter is sufficiently small so that you can examine this range by running the algorithm several times with different values of k.
Note: Partitioning the data into more than a dozen clusters or into a few
dozen clusters is not useful. An application is likely to narrow
down the range to a few k values.