Street Fighter V was thrust into the spotlight of controversy when it debuted in March of this year. Many fans of the series were unhappy with the amount of content it shipped with, especially when in regards to single-player oriented content. This, along with the fact that it was absent from NPD Group's top 10 best-selling games of the month, has led many to believe that it isn't performing well. However, this isn't necessarily true.
According to Capcom, Street Fighter V has sold a total of 1.4 million copies on PS4 and PC. This figure makes it one of the best-selling games of 2016 so far.
In contrast, Street Fighter IV sold a total of 3.4 million units over its multi-year lifetime.
Street Fighter V will rely heavily on post-launch sales to push its number up, and it should be relatively successful at doing so given its strong presence of support; Capcom plans to release new fighters, features, and stages on near-monthly basis.