According to the New York Post, the social networking giant's initiative, currently being tested on one percent of its users, delivers promotions based on real-time conversations.
For instance, if someone posts, 'Thinking of pizza for dinner', a company such as Domino's could ship a web ad to that person in an instant, reports News.com.au.
The advertising test, which was reported in Ad Age, opens a brave new world of real-time advertising, as well as raising the usual privacy concerns when a web company mines personal data for commercial advantage.
"It's an opportunity for advertisers to get in the conversation, and to have that timing advantage is potentially huge," said Paul Verna, a senior analyst with eMarketer.
"But in order for it to happen, Facebook has to pay close attention to not overstepping that balance or risk freaking people out, invading privacy and going over that line," he added.
The firm was serving up real-time ads based on the same information it already gathers on users, only faster, said experts.
It rang up ad revenue of 1.86 billion dollars in 2010, according to eMarketer, which was forecast to more than double to 4.05 billion dollars in 2011.
Promos based on real-time conversations offer a new pathway to advertisers looking to guide purchasing decisions.Until now, search ads were seen as the best way to reach customers when they are closest to pulling out their wallets.