Singles chart question

[anitram]

For our resident experts...

What's the difference between the number of spins kept track of by Mediabase and the Hot 100? I thought that the Hot 100 kept track of radio play and commercial sales of the singles, but sometimes, you have a song jumping up on the Hot 100, while its spins, nationwide are slipping? So what are they looking at?

 

[STING2]

The are a number of reasons why songs increase or drop on the HOT 100 Chart. Even if a songs spins declines, greater declines for other songs on the chart may mean that the song will rise on the chart despite a decrease in Airplay. Sales are another factor which could negate the negative effects of a decrease in airplay.

Airplay on the HOT 100 plays a much larger factor in chart position these days than does sales. Back in the 1980s, it was 50% airplay, 50% sales. Since Singles don't sell well anymore, an artist can have a top 10 hit based on just airplay alone.