Samsung's new Galaxy S IV smartphone is off to a strong start. On Thursday, the South Korean manufacturer announced that global sales for the device have exceeded 10 million units in one month, making it the best selling Android device yet. The company noted that the S IV, which went on sale in late April, is now selling at a rate of four units per second.

By comparison, the Galaxy S III took 50 days after its 2012 launch to hit 10 million, which made it the fastest selling Android phone at the time. The S II needed five months and the Galaxy S seven months to achieve the same milestone. One catch: the sales figures announced Thursday are to retailers and wireless operators, not directly to consumers, meaning that it's not yet clear how many are left unsold in inventory.

Also by comparison, Apple's iPhone 5 sold more than 5 million units in its first weekend of sales, to consumers.

Color Versions

Samsung said it will be offering color versions of the S IV, which currently is only available in black and white. Blue and red versions will be available by this summer, purple and brown in the fall. The S IV is currently being sold in 100 countries, which the company will be increasing to 154.

Some analysts have suggested that the current pace of sales for the S IV is the right one for Samsung, since component shortages may affect supply if demand increases much more. The launch of HTC's One was recently hampered by supply issues caused by a lack of sufficient component availability.

IDC's Ramon Llamas said that the numbers "were not unexpected." He described 10 million as "a good milestone for them," for which the company should be congratulated, but noted that it's "more important to see how they do over the long term."

Tens of Millions

He also pointed out that many vendors "can't even get to 10 million in a quarter," and, from Samsung's overall perspective, "even if the S IV falls marginally short or does marginally better than the S III, you're still talking about tens of millions of units out the door."

The S IV was introduced with great fanfare. It features an 8-core processor Relevant Products/Services, the first full HD Super AMOLED display on a 5-inch, 1920x1080 screen with resolution of 441 pixels per inch, a 13-megapixel camera, and a dual camera function for simultaneously capturing images front and back.

The smartphone has the ability to act as an infrared remote Relevant Products/Services control for TVs and other devices, comes with the latest version of Android and the company's custom Touch Wiz user interface on top, and has a 2700 mAh battery Relevant Products/Services. The new phone also knows when the user is looking at the screen, and a tilt up or down of the phone will cause the screen to scroll. The device can also be set to pause a video if the user looks away from the screen.