Media guardian [free registration required] reports that The Sun is going to scale back its web site in an attempt to reverse a serious sales decline. According to a survey commissioned by the paper, it’s losing some 90,000 sales per day as people read the paper online instead of buying it.

This is where commercial reality meets the “everything must be free and on the net” ideal: reading papers for free online is great for net users and can certainly boost the international profile of publications, but if the ad revenues don’t make up for the loss of sales then the publishers are committing commercial suicide.

If my experience is anything to go buy, online newspapers do mean lost sales. I read the Herald, the Evening Times and the Guardian online, together with various other UK and US papers’ online editions, and on a Sunday I’m more likely to read the Sunday Herald, Sunday Times and Observer online than wander down to the newsagent to get the printed versions. It’s the same with magazines: I stopped buying Wired magazine because it’s a hassle to find in local shops, and because its articles all appear online within a few days of publication; I still buy various film, music and general interest magazines, but without fail they’re the magazines that don’t put all their content online for free.

In the long term technology will solve the problem: electronic paper exists and seems to be good enough to replace printed media, and we’re only a few years away from being able to subscribe to electronic versions of newspapers and magazines that are identical to their printed counterparts and that don’t require a full-blown computer to view them. However, it’ll be several years before such technology is affordable, and it’s entirely possible that consumers will decide that they’re not interested in e-paper at all.

In the shorter term you can expect more titles to do what the Sun is going to do, or what the Telegraph and Daily Mail already do (putting premium content – columnists, features etc – in a paid subscription section). There will no doubt be exceptions such as The Guardian who will continue to offer content for free, but if publishers are given the choice of embracing the internet or staying in business, they’ll choose survival every time.