The NPD Group offered a sneak-peek into their Games Industry: Total Consumer Spend report by revealing that US consumers bought between $2.6 and $2.9 billion of second-hand games, rentals, downloads, and mobile apps during the first six months of 2010.

That's in addition to $3.7 billion on brand new boxed games for their PCs and consoles.

The NPD's total estimate for first-hand games, extra content, hardware and accessories comes to between $9.5 and $9.7 billion.

The new figures represent the first steps in an effort to include the impact of digital downloads and mobile gaming in NPD's analysis of the North American video game market.

This month also marked a cut-back in the level of detail released in NPD's video game sales analyses.

The ten best selling games are no longer given sales figures, meaning that curious industry onlookers are left to piece together scraps of information given out by console manufacturers, games publishers, public relations teams, and various clues scattered by analysts and investors that do subscribe to the full reports.

Additionally, the public chart is now combined, gathering all versions of a game under the same heading and making it difficult deduce how much each version sold.

That said, it was Xbox 360 exclusive Halo: Reach at the top of the pile, selling 3.3 million copies. Only Halo 3 and Modern Warfare 2 had managed to sell more than 3 million in a month prior to that.

The new chart format also brings exposure to titles that may not have made an appearance in a more detailed listing: Metroid: Other M and Spider-Man: Shattered Dimensions are certainly beneficiaries of the new policy, and Disney / Final Fantasy crossover Kingdom Hearts: Birth By Sleep appears in 6th place, a rare feat for a PSP exclusive.

September 2010's best selling video games, USA, all-formats
1. Halo: Reach (360)
2. Madden NFL 11 (360, PS2, PS3, PSP, Wii)
3. Dead Rising 2 (360, PC, PS3)
4. NHL 11 (360, PS3)
5. FIFA Soccer 11 (360, DS, PS2, PS3, PSP)
6. Kingdom Hearts: Birth By Sleep (PSP)
7. Mafia II (360, PC, PS3)
8. Spider-Man: Shattered Dimensions (360, DS, PS3, Wii)
9. Metroid: Other M (Wii)
10. Call of Duty: Modern Warfare 2 (360, PC, PS3)
Source: NPD