A sampler or promotional compilation is a type of compilation album generally offered at a reduced price to showcase an artist or a selection of artists signed to a particular record label. The format became popular in the late 1960s as record labels sought to promote artists whose works were primarily available in album rather than single format, and therefore had little opportunity to gain exposure through singles-dominated radio airplay. Most samplers showcased already-released material, so that as they sampled artists they also sampled the albums from which their tracks were drawn. The term 'album sampler' is also used in cases where an album is distributed among multiple records in case of, for example, vinyl where the maximum play time is less than the length of the full album. In th