Last summer (prior to ARTPOP) Billboard reported Lady Gaga's global sales to be: 25M Albums + 125M singles.
Now that ARTPOP is done, we have new receipts provided by Microsoft:
My calculations are that Lady Gaga is now (actually she has always been) the 2nd best selling digital artist after Rihanna (in fact they'd be tied if they debuted at the same time).
158M records sold WW. Rihanna's receipts are around 180-185M WW.
Katy's sales were reported to be 10M Albums + 90M Singles sold WW (last summer by Billboard, around the same time Gaga's sales were reported) So she is definitely not above Gaga even after PRISM.
And Taylor Swift, Beyonce are also around 100M and 120-130M overall digital sales WW respectively.
So let's applaud Gaga for that amazing accomplishment in the span of 6 years with only 3.5 albums and 15 singles ?
Edit:
Billboard receipts for Lady Gaga's 24M Albums sold + 125M singles sold prior to ARTPOP:
http://www.billboard.com/articles/ne...amed-exclusive