Zynga allegedly authorized an ad agency to plant fake $25,000 bills on the sidewalks of the city on its behalf. Anyone who picked one up would find the address of the Mafia Wars website, where they could get information on Mafia Wars: Las Vegas, the new expansion pack for the online social game.
The city has since had to remove the bills "at considerable expense," according to The Wall Street Journal.
San Francisco is no stranger to viral marketing campaigns as you can probably imagine, but a city attorney spokesman said "It really is a mess; it's worse than stenciling."
The campaign was actually organized by an ad agency called Davis Elen, which said in a statement, "We take full responsibility for the program, regret any inconvenience this advertising has caused to the city and its residents and are working with the city to immediately resolve the issue."
Zynga is one of the biggest web tech companies in the world right now. It has been valued at a whopping $4 billion, and its games have millions of players on web portals and social networks like Yahoo, Facebook and MySpace. It's rumored that the company has made a deal with Google to be a cornerstone of a coming Google Games platform or portal.