Carrier targeting allows advertisers to deliver their ads to users subscribed to specific carriers and often in the same time those on WiFi.
Carrier targeting can be used by carriers themselves, sometimes for comparative advertising purpose, or for carrier-specific services like billing or tracking which are tied with selected carriers.
Carrier targeting is based upon mobile network codes (MNC) or use of IP address databases (at the level of the carrier’s infrastructure).
Carrier targeting is notably offered on mobile networks and PPC search engine platforms. It is not always available for all countries.
See also Wi-Fi targeting.
Carrier targeting on AdWords platform: