A #6 debut is great for any artist, but Lady GaGa isn't seen as any artist. By bloggers, music critics, and her fans she is seen as this untouchable Pop artist who's "weave" cannot be touched.
When the first promo picture for ARTPOP was released music sites and Little Monsters all over-hyped her return calling it a revolution for Pop music and talking about how no one was ready for her slaying. Her, as well as her fans over-hyped the song putting all these theories and rumors about Warhol, Pop culture, art, and what not. They over-predidcted her sales figures and claming it would debut at #1.
Then when Applause was released, everyone saw what it was, a mediocre Pop song that didn't blow anyone away like they thought it would. Followed by her sales numbers which are poor for someone like Lady GaGa.
The song did not meet the expectations and predictions that many people had, not just the Little Monsters, but bloggers, and herself. By those standards the song is considered under-performing and could be labeled as a "flop".
The monsters need to just admit that they over-hyped her and over-estimated her "power" which doesn't seem like it considering we get a new thread trying to justify "Applause".
That's an entirely separate entity from the artist. Let's be real. The debut single was apparently "anticipated" But clearly the public wasn't looking forward to it as much as the people on here 
Opening with 294K with her 2nd lead single is impressive.
every artist has an underperforming single and album at some point.
