London's top three commercial radio stations are all planning on switching to a slightly different system for measuring listening figures which, they hope, will mean more accurate ratings and less fluctuations.
Capital, Heart and Magic all currently get quarterly listening figures from radio ratings body RAJAR which are based on stats from the previous three months. But some argue that the those stats are too prone to seasonal fluctuation, meaning that the top three stations are constantly swapping positions in terms of who has the biggest audience, the biggest audience share and the most listener hours. Those fluctuations have an impact of each station's profits and share price, which no one in the industry likes too much. While the stations will still receive their ratings quarterly, they will be based on listening habits from the previous six months - a system already adopted by Virgin Radio. By taking an average of the RAJAR sample group's listening habits over six rather than three months, the radio groups hope there will be less fluctuations.
Whether the stats prove any more stable with the six month model remains to be seen, though the whole ratings measurement system is so flawed anyway, I doubt it really makes any difference.