Question about album/record sales & Billboard charts

Do they base the top-selling albums in Billboard magazine on actual album sales or the number of albums shipped?

I’ve never figured that one out.

thanks in advance.

Since they started working from the SoundScan system in 1991, Billboard charts have been based on actual units sold, rather than units shipped. Prior to that, they relied on retailers’ reports, which were . . . less than honest. See http://ask.yahoo.com/ask/20020215.html for details on the SoundScan system.

Which explains how the KISS solo albums SHIPPED platinum. Tons of them were shipped back and ended up in cutout bins the country over.

Straight from the source:

Looks to me like it’s both sales (gold) and shipment (platinum, diamond etc).