Even though things are more digital it still doesn't matter an album or single can still be certified without achieving the gold, platinum, or diamond thresholds.
Ex Nicki Minaj "Queen" 700,000+ sales(sps)
Certified platinum
Like everyone has been saying
Soundscan tracks every sale/stream
RIAA doesn't not do the same hence Queen being over certified
If you want a lank go to @chartdata on Twitter then their website and read their FAQ their numbers are from soundscan.