An Odyssey into France best selling albums ever: Introduction
While not directly giving sales figures for specific albums, in case of missing retail and shipment data chart performances are key to estimate the amount sold by each record. Thanks to all retail sales figures available during recent years merged with album market size in France from 1967 to 2015 that chartmasters.org owns as well, it has been possible to create a mathematical formula translating precisely charts into sales estimates.
This kind of methods tend to give awful results when done by someone with no charts and sales background knowledge like infodisc.fr website. This being said, if the formula considers all non-linear values (market size of each year, Christmas market boom, large runs at 1 with sky-high sales, huge number of weeks just off the radar, weigh of the direct competition) and estimates only promotional campaign sales, this method may be a very strong tool. We experienced this formula on 537 different albums released from 1974 (start of certifications) til 1994 (from 1995 Year End Charts based on retail sales are available) that have all been certified within’ their first two years after being dropped, in 529 cases, some 98,5%, calculated sales were consistent with certified levels considering retail sales to shipment sales difference, e.g. sales were over 80% of certified amount and lower than 90% of upper certification level.
From unofficial Top 20 monthly charts in early days to several sets of way deeper charts nowadays (Top 200 new albums, Top 250 Comprehensive albums, Top 100 catalog albums etc), it is obviously much easier to get a realistic estimation for most recent releases, even more with the arrival of retail sales raw data. As a consequence, younger albums will be estimated first, which will enable everyone to increase their understanding of the subject before getting into touchy cases of older albums.
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