In the
United States and the
United Kingdom, a single is usually considered a hit when it reaches the top 40 of the
Billboard Hot 100 or the top 75 of the
UK Singles Chart. The
Guinness Book of British Hit Singles has used this definition since the 1970s. Some argue that reaching at least the top 100—since the
Official Charts Company increased the chart size on their website on 23 June 2007—lets a single be considered a hit due to the increasing singles market after chart rules included download singles. In most cases, the amount of weeks spent on either music chart may also play a big part in its relevance as a 'hit', regardless of its peak chart position. A hit single is variously called a
number one hit, a
top 5 hit, a
top 10 hit, a
top 20 hit, or a
top 40 hit, depending on its peak position. In the UK (where radio play is not included in the official charts), this does not completely reflect the song's popularity—as the weekly chart position is based solely on direct comparison with concurrent sales of other singles. It is, therefore, not uncommon that a single fails to chart, but has actually sold more copies than other singles regarded as "hits" based on their higher chart placement in a period of low sales. (This is also possible in the United States—or anywhere—with slow but steady sellers; a number of minor hits, especially those that are popular in specific genre, have earned gold certifications despite relatively poor pop chart performances.) ==Sales figures==