Recently I've been seeing a lot of people on here saying that having a flop album is detrimental to an artist's legacy, with some even claiming that having a flop album is enough to "demote" an artist from legendary status or say an artist is over.
That brings me to the question at hand.
Does a flop really ruin a legacy?
Let's look at some examples:
Madonna: Perhaps one of the biggest names in music, Madonna has had success that many artists dream of. Recently, however, her album
MDNA underperformed, breaking the record for the biggest second-week percentage drop for a number-one debuting album. The album also failed to be reach platinum certification. So, is this one underperformance enough to take away her legendary status?
Britney Spears: The best selling teenage artist of all time with two diamond certified albums to her name, Spears has outsold some discographies with her first two albums alone. Even so, Spears's latest album,
Britney Jean, was a flop by almost all accounts. The album charted poorly, being Spears's first album to miss the top two. The album has also had lackluster sales, failing to reach even a gold certification. Is this flop album enough to erase Spears's contributions to the industry and all her success?
Christina Aguilera: Often called "the voice of our generation," Christina Aguilera's vocals have been described as some of the strongest in the industry. Aguilera has also found great success on the charts, with one of her albums almost at diamond status. Not to be forgotten, however, is the underperformance of her last two albums. Her last two albums both missed the top two, with
Bionic peaking at number three and
Lotus only making it to number seven. Neither album has been certified in the U.S. Are these two flop albums enough to discredit Christina and her powerhouse vocals and early career success?
Lady Gaga: In a few short years Lady Gaga has done what takes some artists years and years to accomplish. Gaga has had amazing success with singles and albums and has won countless awards, all with only two albums and one EP. Her third offering, ARTPOP, has not carried on Gaga's success, however. The album sold considerably less first week (~840,000 copies) than her previous album
Born This Way, has yet to be certified platinum, and has not produced a single as successful as the ones from her previous albums. Is it fair to say that Lady Gaga is over due to this one flop?
A Lesson Learned
Let us not forget the one artist that proved us all wrong by making one of the biggest comebacks in music history:
Mariah Carey.
Mariah was though to be over after her album
Glitter only made it to number seven on the BB200 and her album
Charmbracelet only made it to number three. Both also failed to impress critics, a big change from her previous material. Her tenth studio album,
The Emancipation of Mimi, showed Mariah coming back with a vengeance. The album debuted at number one, was certified 6x platinum, and produced hit singles (including the song of the decade, "We Belong Together").
So, is it fair to say an artist is over or take away an artist's legacy because of one or two flop albums? Should we discount artists so quickly or learn from Mariah Carey? Discuss.
But she still gets a ton of praise and a name in the industry which is how she makes more money and expands her brand. 
99% of artists flop.