The figures, revealed in the company’s S1 filing with the Securities and Exchange Commission ahead of its upcoming IPO, strongly suggest that Twitter’s data licencing revenue will pass $65m this year. Already, in the first six months of 2013, the company has generated $32.2m in data-related revenue, up 53% on the same period last year.

However, advertising services is clearly Twitter’s real money-maker – and a banker for driving substantial future growth. 2012 ad revenue was $269.4m. H1 2013 revenue was $221.4m.

“We expect data licensing revenue to decrease as a percentage of our total revenue over time,” the company says. In 2012, 27% of revenue came from data licensing. In 2012, that figure was 15%. H1 2013 data revenue is only 13% of total revenue.

Explaining its data licencing business, Twitter said:

“We offer data licenses that allow our data partners to access, search and analyse historical and real-time data on our platform, which data consists of public tweets and their content.

“Our data partners generally purchase licenses to access all or a portion of our data for a fixed period, which is typically two years.

“We recognise data licensing revenue as the licensed data is made available to our data partners.

“In the six months ended June 30, 2013, our top five data partners accounted for approximately 75% of our data licensing revenue, and approximately 10% of total revenue in the period.”

A list of Twitter’s data licensees – at least, those that are part of its Certified Products Program – is available here. Companies/services include social media monitoring and analysis packages like Adobe Social, Attensity, Brandwatch and Crimson Hexagon, as well as data resellers like DataSift, Gnip and Topsy.