The U.S. Promotional Compact Disc Single was borne out of the need to spotlight certain tracks that a record company feels will best promote their artist. These "promo" CD singles are distributed in very limited numbers, usually to select influential individuals, such as syndicated music critics, retail stock managers, radio programmers, and music publishing representatives, who will be useful in promoting the music in advance of its commercial release. Almost always, the Promotional Compact Disc Single (promo CD) is clearly identifiable. It is passed along for important media officials to review, who then choose how best to spotlight the tracks to their specific audience. That is not to say that the everyday consumer cannot obtain these promotional items after they have provided their usefulness to their intended recipients, but these highly sought-after and collectable items are found mainly through specialist retailers and private parties. Sometimes US Promotional CD Singles mimic commercially available CD's both in content and appearance, and other times they may contain exclusive 'edited' versions especially tailored for radio play, or 'remixed' versions geared more for dance-oriented club or radio play. Sometimes they may provide exclusive content in addition to the intended or 'impact' tracks, such as interviews, introductions, short 'call-out research hooks' used by radio programmers for quick on-air song previews, MP3 versions of the impact tracks, or even bonus CD-Rom content used by music reviewers to download images or biographical information. Other times, the Promotional CD Single is nothing more than a simple one-track version of a spotlighted track. Often times, the Promotional CD Single will feature artwork on the disc and/or on its sleeve or inserts (when available) that differs in appearance and content from any other regularly available release of similar material by the same artist. One thing is certain -- since the first appearance of the U.S. Promotional Compact Disc Single in the late 1980's, it has endured as an important and integral component of both the novice and experienced music collectors' personal inventory.