Madonna is way ahead of her overall (Soundscan only started tracking sales in 1991 and club sales are not included). Both Britney and Madonna have sold more than this.
I never understand why Billboard ignores millions of Club sales and pre-Soundscan sales.
Shipped albums opposite to actual sales, albums counted as sold multiple times, albums sold for less than one dollar, labels claims etc.
I found it:
4) In the 1990's, but also earlier in the 80's, there were something that we call "Music Clubs".. You could become a member of a certain music club (and many labels had those for example BMG and Columbia/Sony) and pay a monthly fee to get music cheaper. You ordered the album directly from the label. Those sales were never counted by soundscan, only the RIAA tracked those as the label proved that they've sold for example 500,000 copies on one album to randon members of their music clubs.
