The figure was one of many shared by Kevin Beatty, chief executive of DMG Media, who was speaking at the World Newspaper Congress in Bangkok.
Beatty told the conference that by gathering audience data for the Mail Online and other digital titles in the portfolio, the company learns "50 billion things about 43 million people over a 10-day period".
"We now have an increasing level of insight on the 31 million people on our central database," he said. "By leveraging our combined data across the group, we are able to share real information with our businesses to help serve our customers better and to find new ones."We have learnt to embrace the internet for what it is, not what we would like it to beKevin Beatty, DMG Media
The latest audited circulation figures show the Mail Online had 119 million readers globally in April, 42 million of whom were in the UK, plus there were nearly 900,000 readers of its iPhone app and more than 500,000 using the Android app.
That "huge audience" is the "cornerstone of our own sales network where we track behavioural data of 52 million unique browsers", Beatty expained.
He said he does not really understand how the audience data is measured, "but one of the things I am learning fast is to how we should use it and how we should actually deploy it better".
He gave a real example of an anonymous user. Data shows this person likes competitions, that she has a clear interest in showbiz and fashion content, that she has tried to quit smoking, plus where she lives and gives many of the details of her family.
Innovation in commerce and advertising
DMG Media expects digital revenue to exceed print advertising revenue by 2015, Beatty said, explaining audience data is the key.
"Understanding consumers at this level of rich data is critical to our future. We can utilise this drive the behaviours we seek, and to bring innovative marketing solutions to our advertisers," he said.
One such solution has been to launch a Groupon-style daily deals business called Wowcher, which now has 2.5 million subscribers and is the second largest daily deals offering in the UK.
Consumer data "also allows us to sell products and services directly through our growing commerce division", Beatty explained.
"One of the things we know through our rich customer data is that our customers continue to want to buy travel, they continue to want to look at financial products, they continue to want to look at other products and services." And sometimes this involves cutting out the middle man and "looking for that opportunity for ourselves".
Keeping it free
"There's a prolonged and sometimes passionate debate about paywalls," Beatty said.
He told conference delegates that publishers have three options to choose from, depending on what their purpose is and what they want to achieve.
"You really have as a content site three choices: serve a niche and charge; bundle digital and print to your existing customers and hope to generate some new customers; or you can, as we have chosen, go for new customers at scale and stay free."
Beatty argued that the Mail Online audience is closer in scale to global players, like MSN, Yahoo and AOL Huffington Post, and to some TV networks like CNN and BBC News, than it is to newspaper websites.
Referring to the digital-native sites such as MSN, Beatty said we know that none of these news sites are likely to start charging any time soon. "So if we want to compete with these players on that scale, we have to remain free."
He also explained that DMG Media has an "ambition to get people engaged on the web and on their mobile devices with Mail Online in terms of 30 to 40 minutes, which is around the average time that people can spend reading a newspaper."
The free-to-access model has led them to new customers both in the UK and globally. "We have learnt to embrace the internet for what it is, not what we would like it to be," he said.
Journalism.co.uk is in Bangkok for the World Editors Forum and the World Newspaper Congress. Follow @SarahMarshall3, @JohnCThompson, #editors13 and #wnc13 for updates.