Whopper Sacrifice was an advertising campaign by Burger King which was launched in January 2009.

[1][2] After unfriending 10 people on Facebook, people were eligible for a free Whopper by Burger King.

Apparently, Burger King told them that they were worth “1/10th of a Whopper”.

The app was disabled by Facebook.

[3] The campaign was developed by Crispin Porter + Bogusky.