Why is The Sun losing sales faster than its traditional rival, the Daily Mirror, and its closest competitor, the Daily Mail? And why is it doing so when it is 10p cheaper than the Mirror and 20p cheaper than the Mail?
These are questions I pose in my column in today's London Evening Standard. It strikes me as significant that the gap between the Sun and the Mirror just a year ago was 1.5m and now it's down to 1.2m.
Similarly, the gap between the Sun and the Mail has narrowed from 644,000 in June 2012 to 437,000 last month.
This is an unprecedented reversal of fortunes for The Sun. It indicates that in just 12 months Britain's best-selling daily paper has been growing less and less popular, declining faster than the rest of the market.
As I argue in the Standard, it is unlikely that the negative publicity surrounding Rupert Murdoch, the now-defunct News of the World and The arrests of Sun journalists are reasons for buyers deserting the title.
But those factors will have played their part internally, sapping morale among the journalists and also making editorial decisions much more tentative. And the one thing The Sun can never afford to be is tentative. Its USP is iconoclasm.
In others words, The Sun has lost its confidence, which may well not be too surprising in the circumstances. The arrests of journalists for allegedly paying police and public officials for information has also undermined its traditional news-getting practices.
There are also political headaches that complicate its editorial agenda (see the Standard piece and my posting here last week).
It's no wonder that Murdoch thought it time to replace Dominic Mohan as editor with David Dinsmore. But a new man in the chair is unlikely to have much effect in the short term, if at all. The downward sales trend appears to be relentless.
I also see another problem for The Sun as its website heads for a paywall next month. It is essentially a British, rather than an international, product.
Its audience, already drawn mainly from the UK, is extremely unlikely to expand abroad once it charges for online access.
In truth, News International (as was) - and Trinity Mirror, incidentally - allowed Mail Online to secure a firm foreign foothold, particularly in the United States. Too few resources at The Sun have been devoted to digital (and, clearly, too little thought).
The print sales figures do not suggest that The Sun is facing an immediate crisis. But they do point to a problematic future.
