Sleeping Dogs sales reached 172,000 during its two weeks on sale during August.
The NPD Group shared the figure with Joystiq.
That figure doesn't include PC sales, because the data only covers retail - and there's no physical PC release in the US. This bit is quite interesting, as Sleeping Dogs on PC isn't a cheap-and-nasty port, and has drawn significant praise from the Master Race. It frequently appears in the top 50 games being played on Steam.
The United Front open world effort is available on PC, PlayStation 3 and Xbox 360.