Why are some tracks not available to buy individually?

A small number of tracks can only be bought as part of a whole album or single, and cannot be bought individually. This is because they are either very short or very long. In the case of very short tracks we don't believe it is fair to sell them for the full price of an individual track. In the case of very long tracks (duration of longer than 10 minutes) the relatively low price of an individual track is not in fair proportion to the length of the track. If you download these longer tracks as part of an album then the cost per track should not exceed $0.99.