In a deal that is being closely watched by the advertising sector, Twitter (News - Alert) is expected to raise several hundred million dollars in revenue through the Starcom Media Vest Group (SMG).

The agreement, which still needs to have some details worked out, was described by The Telegraph as the micro-blogging site’s “biggest ever advertising deal.”

Also, SMG, a division of Publicis, was described by the BBC as “one of the biggest players in U.S. advertising.” Its clients include major advertisers, such as Proctor and Gamble, Microsoft (News - Alert) and Coca-Cola.

Under the deal, SMG customers will receive “preferential access to the best advertising slots on Twitter,” the BBC says. It was also reported that SMG will get access to Twitter data and research. In addition, there could be a “direct feed of data” from Twitter into SMG's tools.

The platform provides many other benefits to businesses. With Twitter, marketing can directed “to very precise groups of people, based on their age, gender and the interests and affiliations they have expressed through interaction with social media,” the BBC explained.

“In about 18 months Twitter has gone from an experiment to [being] essential,” Laura Desmond, CEO at SMG, said.

In addition, Advertising Age reported that the move is “both a big vote of confidence in Twitter and a sign of how seriously marketers are now taking [the] platform.”

Lisa Weinstein, president of Global Digital, Data and Analytics at SMG, also told AdWeek, "It's not just about inventory and ad products themselves. It's about how we better understand consumers across screens with platforms like Twitter and mobile devices. It's so much more than just an agreement around inventory and ad products."

The deal is part of an important trend for Twitter given that ad revenue is predicted to almost double in 2013  compared to 2012, eMarketer (News - Alert) says, based on a BBC story.

eMarketer predicts Twitter also will earn $582.8 million from advertising during 2013, and in 2014 may earn as much as $1 billion from ads.

At the start, Twitter displayed no ads, but that has since changed. It started in 2010, when it started to offer paid advertising for companies, referred to as “promoted tweets,” TMCnet reported.