It’s a milestone day today. First, Apple announced it sold three million new iPads over the weekend and now South Korea-based Samsung confirmed it beat its own self-imposed estimate by shipping a respectable 30 million units of the flagship Galaxy S III handset. Previously, executives for the company publicly expressed hope to move that much units by year’s end. The Galaxy S III launched back in May so the figure amounts to an average of six million S III units a month…

Samsung basically added a cool ten million Galaxy S III sales in the last 50 days. Its execs early-September publicly set a target of selling 30 million S III units by year’s end. Ahead of the iPhone 5 release, watchers pondered whether Apple would be able to beat Galaxy S III sales and re-take its crown of America’s best-selling handset.

Apple sold 26.9 million iPhones last quarter. Samsung last year stopped divulging tablet and smartphone data for competitive reasons, but various estimates paint its smartphone market share as twice that of Apple’s.

In comparison, club Cupertino sold five million iPhone 5 units during its opening weekend. Apple’s latest phone went on sale on September 21 in just nine countries, rolling out in 22 more countries a week later. According to one survey, Apple’s handset surpassed Samsung’s flagship product in web traffic volume in just 18 days.

To share the exciting news, Samsung took to its official blog, where mobile head JK Shin compared the figure to the Galaxy S II, which shipped ten million units in five months.

The Galaxy S III continues to be a runaway favorite with customers around the world. Meeting this sales milestone in five months sets another record for Samsung, and we are extremely proud and yet motivated to continue to provide our customers with products that they love.

For the record, I just got my Galaxy S III last week. So far, I’ve been pretty impressed with its build quality and overall speed, even if Android doesn’t take full advantage of the underlying hardware.

Of course, I like the iPhone 5 better.

Are you surprised by this milestone for the S III?