Record sales sure aren't what they used to be -- these days, even a legend like Madonna has a hard time selling half a million copies of her latest album.

Her 12th studio set, 'MDNA,' sold more than 350,000 units during its first week on the charts back in March, but it's been on a slow sales crawl ever since; the Recording Industry Association of America (RIAA) awarded it with gold certification (triggered after 500,000 units) just this week.

As the Hollywood Reporter notes, 'MDNA' faced an uphill climb almost from the beginning: After notching healthy first-week sales, it suffered a drop of more than 85 percent, the biggest for any artist since SoundScan tracking was implemented in 1991.

Although her 'MDNA' certification marks Madonna's 20th gold album and adds another pile to her impressive sales total of more than 64 million records and counting, it represents an incredibly steep decline from her commercial peak during the '80s, when she moved a mind-boggling 71 million albums worldwide between 1983's 'Madonna' and 1989's 'Like a Prayer.' And she hasn't just been a victim of changing times on the album charts, either -- while 'MDNA' managed to spawn one top 10 single in 'Give Me All Your Luvin',' neither of its two follow-ups broke the Hot 100.

Watch the Madonna 'Give Me All Your Luvin'' Video Feat. Nicki Minaj + M.I.A.