Subscription revenues for FT.com have risen 43 per cent year-on-year, helping the newspaper keep in profit for 2009, the Guardian reports.

But its management has also flagged up the potential in other areas, too: BBC technology correspondent Rory Cellan Jones’ interview with FT.com managing director Rob Grimshaw touches on the money-making potential of registered news site users – who don’t necessarily pay.

What’s interesting is that the middle group, those who register but don’t pay, are still proving lucrative. The 1.9 million people registered users have given some very basic information such as their job title.

That’s enough, according to Mr Grimshaw, to allow the FT to run a targeted advertising and marketing operation with high yields.

While the FT’s higher tier of paying subscribers brings in around £20 million a year, it is still thinking about the freeloading clientele.

So are non-paywalled publishers missing a trick by not setting up registration systems, for fear of traffic drop-off?

It’s perhaps worth going back to my interview with Rob Grimshaw in January:

User analytics
Monitoring the behaviour of 1.8 million registered users and 121,000 subscribers is a big part of the FT’s marketing strategy, he said.

“Their details are in a database: we have a lot of demographic information about them; we’re also able to combine that with their normal activity on the website. That data base is a goldmine that brings benefits to many parts of the business.”

Specific advertising can be exposed to a certain audience and direct communication can be made by email, he said. “1.8 million users have self-selected as people who are interested in our content and our business,” he added. “It is an area where there are enormous benefits to be gained.”

He argued that privacy is not infringed by the publication’s methods: “We never focus on behaviour of particular individuals: we are always looking at things in aggregate; how a sector of our database of users behaves.

“We would never allow an advertiser access to that [user information]. That would be both unacceptable and illegal.”

The success of companies like Amazon was due to carefully targeted marketing, he said:

“Some of the most successful companies out there have built their businesses by understanding the behaviour of their users in a very defined way; using their insight to develop their business decision making.”