At my job at the Archives of Traditional Music metadata is critical to identify digital audio files and associate related documentation and physical recordings to each file. ATM uses its own software to collect data such as: size, track-configuration, tape brand, length, reel-size, tape thickness. The software also collects data about the structure of the side of a tape, and associates related files and derivative files to other files. Just like mp3s can include ID3 tag data about artist names, album titles, and song titles, .WAV files include RIFF metadata that embeds metadata into the end of the file. This is important because if there is an IT catastrophe, files can be identified through their metadata.
Embedded metadata is important because it can leave a trail for the origin of a digital file. It doesn’t need an additional file to go along with a recording or image that can be misplaced. Metadata allows the file to stand alone and also gives critical context that can be lost otherwise.
Metadata is useful for websites and search engine optimization as well. As metadata tags can categorize and describe pages better than a semantic reading of its context could, they are more efficient.