We know that the Nokia Lumia 920 is an extremely well-received handset, with retailers around the world claiming they run out of stock the minute they get some new units in. However it seems that while we can’t deny the popularity of the Lumia 920, part of the reason why retailers are finding it hard to keep it in stock is because Nokia isn’t producing enough units to keep up with the demand. According to leaked information from one of Nokia’s factories in Beijing, it was revealed that Nokia is only producing 2 million Lumia units a month, 20,000 units a day for the Lumia 920 (about 600,000 a month), 25,000 Lumia 820s and the 20,0000 Lumia 620s, which means that less than a million Lumia 920s are made every month. Assuming the leaked information is to be believed, this could explain why some retailers are finding it hard to keep Lumia 920 units in stock – partially due to its popularity and the lack of units available.