This is along the lines of what stardusties was saying about people not buying singles in the US. The US (and European) retail singles market is not what it once was. An example of this would be the Billboard Hot 100. Up until about six years ago, the chart was based on retail performance. In 1998, the chart was changed to factor in other things, such as radio play. The decreasing retail market for singles was one reason why this was done.

In Japan, retail singles are still a major factor in the grand scheme of things. While the market may eventually take the same path as the one in the US, for now, it is holding up. One part of the promotional process in the Japanese industry I really enjoy is the music shows, such as Music Station and Pop Jam. While similar shows exist here in the US, like TRL, and music artists often appear on talk shows to promote their latest works, there isn't a main program I can turn into to see all the major stars on a weekly basis. This relates back to the difference in the way singles are handled in each country.