Since its release a month ago in April, the Samsung Galaxy S5 is off to a great start with its new smart phone device, already selling more than 11 million units since its launch.

Samsung's CEO, JK Shin told the Wall Street Journal that the Galaxy S5 is doing so good that it surpassed Samsung's S4 model in its first month by 10 percent.

"It's been a month since we began selling the S5, and out of the gate, sales are much stronger than the Galaxy S4," Mr. Shin said.

He also commented that sales were especially booming in developed markets such as the U.S., Australia and Germany.

Last year when Samsung introduced the Galaxy S4, it only sold 10 million units in its first month.

Despite Samsung's success with its Galaxy series, PC World reports that not all the critics have been happy with the device. In particular, reviewers have been disappointed with the phone's plastic casing that they said gives the handset a cheap feel. Others have said the fingerprint scanner and heart rate monitor don't always function properly.

Since the negative reviews, Samsung has named a new Vice President head for its mobile products design team, Min-hyouk Lee. Samsung's previous head, Dong-Hoon Chang now focuses on longer-term design of the company's products.

So now that the Galaxy S5 is doing well, we are left to ask, "What's next?"

According to WSJ, Samsung executives plan to roll out variations of the phone over the next few months in different countries. Samsung is also expected to launch a successor to Galaxy Note 3, the company's popular large-screen phone, in the second half of the year.

There are also talked of a prime version of the Galaxy S5 in the works, so Samsung consumers can look forward to all that's in store.

Will you be purchasing?