Targeting specific carriers in Android

I read here: http://www.androidguys.com/2009/10/11/developers-can-now-target-by-carrier-in-android-market/ that it can be done if you go to the Android Market, and go to your app, then go to Publishing Options -> Locations, but I don't see anything to select a specific carrier there, only specific countries.

Is this something that Google changed? Can this still be done, or is it done automatica开发者_StackOverflow中文版lly? Can't the carrier be detected from the device?

Un-check "All Locations"

Then find the Country that you want to limit by carrier. Click on the country's name, it is a hyperlink. This will then reveal the carriers for that country underneath it, such as US has

• All Carriers
• AT&T Mobility
• Sprint
• T-Mobile - US
• Verizon Wireless
• nTelos

Example: