It is commercially hit but under performed taking expectations from the series.
More fans have been moving away from the series than the no of new users the game is getting.

So in short : game isn't flop but resident evil series will loose AAA title now.

Expectation from next game will be reduced to 2 -3 million lifetime.

Sorry this wasn't a flop.

Second that

Companies don't look at just the sales for the current game. It's also a question of consumer goodwill, which is extremely important in this industry.

A poor game lowers the expected sales for the next game in the series greatly.

As such, the value of the resident evil series to capcom was diminished after resident evil 6. Thus, flop.

i love your sig

Seeing how Resi6 on the PS3 didn`t sell half as good as Resi5 (which already was considered a bad Resident Evil by many) you seem to have a point

3.6m sold through is not a flop. Maybe if Capcom had made an absurd sales projection of something like 10m expected sell through it could easily be called a flop, but as it stands, RE6 will likely end up breaking the 5m mark eventually between discounted copies and the inevitable "Gold Edition" with all the DLC on disc.

Capcom has already squandered the reputation of the RE brand with Raccoon City, so I really don't see RE6 sales as further damaging the franchise, but it is pretty clear that the franchise should probably be taken in a better direction in the near future if they want to revitalize the brand.

Everyone keeps saying "return to the series' survival horror roots." Maybe someone with executive power at Capcom will actually listen.

Spinoffs dont do the same damage as a numbered sequel.  They lowered their forecast meaning stocks will be taking a big hit and the future of resident evil is now going to make people second guess.  This is the word flop used in a way of saying it underformed and was lacking.  Both which is true.  Flop has many different meanings, it does not necessarily mean failure.