Sony PlayStation 4 sales surpassed the 7 million mark earlier this month according to the console maker, and Microsoft, its biggest rival, has some work to do if it wants to stay competitive for gamers.
One of the major drags on Xbox One sales is the console's price, according to Jeremy Rosenberg, head of digital at Allison+Partners. When the console launched in the United States last November, its list price was $499.99. That's $100 more than the PlayStation 4.
"Price drops are an inevitable part of the console gaming enterprise. They will drop their price eventually. ... But I think that $100 definitely is causing some people to go with the PS4," said Rosenberg, who added that he expects the Xbox One price to fall by the end of this year.
Read More Why the PlayStation 4 is outselling the Xbox One
"They also had the challenge with [Xbox] Kinect being front and center, and I think in this new kind of post-Snowden era, some people are a little bit hesitant to put a camera right in front of the television," Rosenberg said.
And based on sales of games for previous console models, Microsoft might be relying too heavily on exclusive games to drive console sales, according to Rosenberg.
"Halo 3," the best-selling game for the Xbox 360, was sold to more than 25 percent of console owners, while the best-selling PS3 title, "Grand Theft Auto San Andreas," was purchased by about 12 percent of those console owners, Rosenberg noted.
—By CNBC's Althea Chang.