Her first four eras were amazing and perfectly handled. People were so obsessed with Britney and everything around her by the early 2000s it was out of this world. She made a hit with every era, she had memorable performance, appearances, videos, singles, smiles, etc;
Then, as people were highly obsessed with Britney, when she stopped making music to try to have a normal life with Kevin and then everything went downward spiral, people became even more interested in her. The fact Blackout sold considerably well and spawned hit-singles (or moderate hit-singles if you will), proved how much the GP (or her fanbase if you think so), wanted Britney to "comeback".
Like it or not, Britney Spears will ALWAYS be a factor. Britney herself tries to kill her career and she can't.
