Any song released during the digital era can only be considered a classic if it passed 7 million sales, as it takes tremendous longevity and cross demographic appeal for a song (qualities that makes a song a classic) to sell 7M
"I Gotta Feeling" 
"Rolling in the Deep" 
"Party Rock Anthem" 
"Somebody That I Used to Know" 
"Call Me Maybe" 
"Thrift Shop" 
"Poker Face" 
"Blurred Lines" 
"Radioactive" 
"Low" 
"Cruise" 
 
"Just Dance" is coming too
