Lets face the facts, in terms of popularity Britney Spears is far ahead of Christina Aguilera. In total, Britney is far ahead of Christina in album sales. Only one of Christina Aguilera albums made it to #1 on the Billboard while all 4 of Britney’s albums have made it to #1.
Also, when you look in magazines, even tabloids you hear about Britney Spears everyday, rarely Christina Aguilera. Its because the public is more interested in Britney and a tabloid with Britney in it will sell more. Britney’s tours do very well and she often sells out shows and appears on HBO and Showtime live broadcasts, even though she has no other major artists with her. On the other hand Christina needs to tour with a massive artist like Justin Timberlake in order to fill a sufficient amount of seats, as we can see, when she even tries to tour with no major opening act her tour flops and is quickly cancelled. I guess the Madonna kiss when they both kissed her and BRITNEY ended up getting the attention and Christina was left complaining about how no one noticed her summed it up. Christina will always be in Britney’s shadow.