Chatroulette, which connects webcam users at random, has previously been a no-go area for high-profile advertisers because of the risk of brands being hijacked.
However, Giffgaff has started promoting itself on the service using frontman Pierre, who has been commissioned to draw caricatures of Chatroulette users while talking to them.
Giffgaff also plans to provide a code via Chatroulette that will let users claim SIM cards with free credit when they register on the network's website.
Giffgaff claims to be a new kind of mobile network with no call centres, glossy TV ads or ‘weasel pricing'.