Her first album sold 25M copies, less than 1/3 of her career total.
Her first era sold less than 10M singles, less than 1/9 of her career total.
Her first tour grossed $35M, less than 1/13 of her career total.
And it's a shame that all the longevity in the world won't help the likes of Bey, P!nk, Rihanna, Taylor Swift, etc. reach the career magnitude that Britney saw right out the gate