Killzone 2 managed to sell 323,000 units in the first 2 days of release according to the NPD results for February, and the game has continued to sell well in Sony's eyes. Scot Steinberg has confirmed that Killzone 2 has sold at least 500,000 units in it's first month of release.

"We have exceeded our expectations with Killzone 2 – it shipped on February 27, which means there were only two days reported in the month," said Steinberg. "It also set the record as the most pre-ordered SCEA PS3 title to-date. Our PR metrics to date are also very strong, with a 92 average review score."

He went on to say "Killzone 2 has been the fastest SCEA PS3 title to break the 500,000 unit mark and it's also the highest selling SCEA PS3 title for the first 30 days out of launch," detailed Steinberg. "So far, we are extremely happy with the results."

Source GameDaily