Her big success, she reached relatively young. For example:

 At 17, she won as the youngest singer in the U.S.  the album and single charts.

 To date (2011) ... Baby One More Time is the biggest selling debut album of an artist, which appeared in the U.S. ever.

 Their second album "Oops! ... I Did It Again" sold in the first week in the U.S. alone 1.3 million times. Worldwide 2.4 million times in the first week.

 In the period from 1999 to 2006,  Britney Spears sold more records than any other artist.

 She is the youngest singer ever on the "Walk of Fame" immortalized in Hollywood.

 The youngest woman in the history of the U.S. charts, which landed five albums at number 1, and is the first performer ever since Elvis Presley, who managed this feat. 

 Spears has sold in the U.S. of all female artist most albums in the decade (2000-2010) and ranks in 2nd place behind Eminem. 

 Spears has sold in the decade (2000-2010) not only the most albums, but she also had the world's most hits. In the world charts she reached with 18 songs (including seven # 1) Top 10 - more often than any other artist in that period. 

 Spears is the first artist who has achieved over the last three decades (90s, 2000s, 2010s) at least one number 1 in the USA.