Data source: Press Gazette (The right-hand column is mine.)
Why so large? In part, possibly because of Mr George Carron Greig's editorship since he took over the DM from Paul Dacre. The new line on Brexit, vilifying those who are trying to see the result of the Referendum put into practice, will have repelled many readers.
As Dacre warned in the Spectator:
"Support for Brexit is in the DNA of both the Daily Mail and, more pertinently, its readers. Any move to reverse this would be editorial and commercial suicide."
Further, it is my impression (and do please correct me if I am wrong) that Greig's Mail on Sunday was (still is?) supportive of Scottish independence-while-simultaneously-remaining-in-the-EU. This oxymoronic nationalism is a strange confection also espoused by the otherwise penetrative intelligence of Craig Murray and I can only understand it in terms of an almost gibbering atavistic hatred of the English. Or maybe something akin to that expatriate sentimentalism that causes New Yorkers to drink Guinness on St Patrick's Day, even if they're not of Irish descent.
Odd, you may think, that Lambeth-born, Eton-and-Oxford educated "Geordie" Greig might (if I interpret him rightly) take this stance towards bonny Scotland; but his father served valiantly in the Scots Guards during WWII and it's just possible that there may be family tradition at work here.
Which is why I recently wrote him a letter explaining the reason for cancelling my subscription, and concluding:
"May I also say how illogical it seems for a Scot to desire independence for his country within a profoundly undemocratic and micromanaging European Union, moreover a Union determined to become a single nation in which Scotland’s fate is to be a negligible backwater; and how contradictory it seems for him to wish this peculiar freedom for his country while doing his best to deny genuine self-government to the rest of the United Kingdom."
If I'm wrong about him, then perhaps I've made a fool of myself - not such a big task, really. But if I'm right, then I look forward to a Stuka-like further nosedive in Mail readership.
P.S. Bad Maths!
The total actual losses in sales should have been calculated by reference to the levels of a year before. But that would support my general point even more re DM/MoS readership haemorrhage vs current readership of the Guardian/Observer.