Fever was an album sold on the Internet.
 Albums of recorded sound were developed in the early 20th century as individual 78 rpm records collected in a bound book resembling a photograph album; this format evolved after 1948 into single vinyl long-playing (LP) records played at 33+13 rpm
 The song is not necessarily free nor is it available as a stand-alone download, adding also to the incentive to buy the complete album

