SAN FRANCISCO: Twitter, the social network, has unveiled a new advertising platform that it hopes will attract brands and effectively monetise its service.

The ad programme, Promoted Tweets, is based on a similar approach to Google, with marketers buying up keywords, and their posts appearing at the top of a list when users enter relevant search terms.

Overall, the aim is to give particular prominence to the comments added by these firms, which can otherwise be subsumed in the vast amount of other traffic available about their products.

"The idea behind Promoted Tweets is that we want to enhance the communications that companies are already having with customers on Twitter," said Dick Costolo, Twitter's chief operating officer.

"The ability of companies to engage with customers around this interest graph is more compelling than trying to wedge yourself into these social interactions."

In choosing which specific tweets to highlight, Twitter will employ nine metrics, such as the number of people who replied, forwarded it on to their "followers" or clicked on the links it contained.

Best Buy, the consumer electronics firm, Virgin America, the airline, and Starbucks, the coffee chain, have all signed up to this service thus far.

Chris Bruzzo, vice president of brand, content and online at Starbucks, said this strategy would help the corporation alert its target audience to promotions and other news they could be interested in.

"When people are searching on Starbucks, what we really want to show them is that something is happening at Starbucks right now, and Promoted Tweets will give us a chance to do that," he argued.

The other functions of Promoted Tweets might include respoding to negative word-of-mouth, such as unfavourable comments made about films.

However, Bernardo Huberman, senior fellow and director of the social computing lab at Hewlett-Packard's research and development unit, said this may prove challenging.

He has previously assessed how movie studios endeavoured to employ this channel to respond to critical commentary regarding their output, and found that the results were far from optimal.

"Our study shows that the influence of those tweets was minimal compared to the conversation that people were having about those movies," said Huberman.

"Media like Twitter and Facebook are so enormous that it's very hard to imagine it would be easy to manipulate the conversation."

While advertisers will initially be charged in terms of cost-per-thousand, Twitter could adapt this approach once its advertising system is up and running and more detailed data is available.

Looking forward, the company is also considering inserting Prominent Tweets into "relevant" conversations on its pages, but will not seek to do so immediately.

"We want to get this right. We don't want to force a model on people that is based on incorrect hypotheses," said Costolo.

According to comScore, the research firm, Twitter's user base had reached 22.3 million people in the US by March 2010, up from just 524,000 a year earlier.

Moreover, this estimate did not incorporate the vast number of people who access the social network via smartphone applications and similar online tools such as TweetDeck and Tweetie.

Data sourced from New York Times/AdAge; additional content by Warc staff