Apple's biggest rival in China sold $335 million worth of phones in just 12 hours

Xiaomi, the red-hot startup often referred to as the "Apple of China," has sold more than 2 million smartphones in a 12-hour flash sale.

The company held a "Mi Fan Festival" to commemorate its fifth birthday, managing to shift 2.12 million phones over the course of the day, with a recorded revenue of $335 million.

Xiaomi's fans are famously devoted to it. The Chinese company goes to great lengths to court them, including these "festival" flash sales, heavy engagement on social media, and even throwing parties in expensive nightclubs for their most loyal fans. And the strategy works - in just five years, the company has grown from nothing to become the most valuable startup in the world, despite spending far less (as a percentage) on marketing than rivals like Samsung.

For reference, over the entire launch weekend of the iPhone 6 and 6 Plus in September 2013, Apple sold 10 million devices. This works out as similar numbers per hour as Xiaomi's "festival" - but unlike the Apple launch, Xiaomi launched no new products for the flash sale.

In addition to phones, Xiaomi also sold 38,000 Mi TVs, 247,000 Mi Power Strip fitness bands, and 770,000 smart appliances. It's the company's best-ever single day online sales performance.

Xiaomi doesn't intend to come to the US "for a few years," according to exec Hugo Barra. But its continued growth will be of concern to Apple, which under the direction of retail head Angela Ahrendts is in the midst of aggressive expansion in China, Xiaomi's home turf.

Previously, Xiaomi's smartphones have been derided as cheap copies of Apple devices, with Apple design chief Jony Ive even labelling them as tantamount to "theft." But more recent models have eschewed the Apple aesthetic in favour of a distinctive clean design, and reviews suggest its products may actually be technically superior to Apple's.