Interesting new numbers - looks like PSP is VERY popular in a lot of Asian countries that VGChartz (unfortunately) can't track. These are likely VGChartz missing numbers.
Here are the official numbers from Sony (breakdown by region):
Q: What is the breakdown of unit sales by territories and/ or by models (1000/ 2000/ and 3000).
- SCEA: Approx. 18 million units
- SCEE: Approx. 16 million units
- SCEAsia: Approx. 4.5 million unit
- SCEJ: Approx. 11.5 million units
(The numbers include bundle packs released from 3rd party publishers) We do not disclose the breakdown by models.
UMD software sales/ breakdown by territories (sell-in as of Dec 2008)
- WW: approx 200 million (197 million)
- SCEJ: approx 36 million
- SCEA: approx 81 million
- SCEE: approx 76 million
- SCEAsia: approx 4 million
http://www.el33tonline.com/past/2009/2/16/sony_reacts_to_psp_reaching_50/