In the latest month the gap grew by 188,453 units in favor of the PSP and by 567,045 units in favor of the PSP in the last 12 months. The PSP currently leads by 1.98 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 71.62 million units, while the PSP sold 73.59 million units….

3DS vs PSP VGChartz Gap Charts March 2018 Update

Source: PS4 News – 3DS vs PSP VGChartz Gap Charts March 2018 Update