VGChartz's William D' Angelo: "3DS Vs. PSP Global:
Gap change in latest month: 1,577,671 – 3DS
Gap change over last 12 months: 2,519,552 – PSP
Total Lead: 5,328,173 – 3DS
3DS Total Sales: 57,801,748
PSP Total Sales: 52,473,575
In the latest month the gap grew 1.58 million units in favor of the 3DS, however, that only partially offsets the gains the PSP has made in the last year. In the last 12 months the gap has shrunk by 2.52 million units. The 3DS currently leads by 5.33 million units.
An important note is that the two handhelds launched at different times of the year. The PSP first launched in December 2004, while the 3DS launched in February 2011. The 3DS has sold 57.80 million units in its first 58 months, while the PSP sold 52.47 million units."