If you value the news then don't let newspapers die
What does it cost me to go on Facebook? As I haven't got round to installing an online ad blocker, the price of connecting with my friends is that I have to endure the daily humiliation of companies trying to sell me weight-loss pills.
This so-called 'targeted' advertising is the reason why Facebook was able to float for more than $100bn (£63.7bn) this month.
We - its users - think we are sharing our information with friends. But Facebook is then sharing our information with advertisers all over the world.
Facebook is not a benign giant kindly offering us a free service to make our world a happier place. If anything, it should be paying us for the privilege of seizing our data and selling it on.
We are generally fond of Facebook, Google and Twitter because they lubricate our lives. But the business of Big Data is as impersonal and powerful as that of Big Oil - worse, because it can exploit our personal lives in a potentially far more intrusive way.
How has this happened? It's partly our fault for being so reluctant to pay for anything online. We feel entitled to something for nothing and then fail to appreciate the price of free.
If Facebook were to offer its services for, say, £5-a-month and promise not to share any of our data, how many of us would sign up? My guess is 10% at most.
Banks have come up against the same obstacle. We are used to free current account banking - a tradition a Bank of England director, Andrew Bailey, lamented last week. Bailey claims that free banking is a "dangerous myth", which has encouraged banks to engage in mis-selling products, such as payment protection insurance.
A more dangerous myth - at least for my profession - is that good journalism can be consumed for free. If you are reading this on paper: thank you. If you are reading it online, you are hastening the demise of the well-informed journalism that I presume you value. The revenue generated by online ads doesn't come close to covering the costs of producing a decent newspaper.
At a Google conference last week, I heard panellists gushing about 'citizen journalists', as if they were comparable to the paid-for variety. But we don't have 'citizen brain surgeons', or 'citizen airline pilots'.
Journalism is a profession and its practitioners spend decades building their specialist knowledge, nurturing contacts and honing their expertise, so that their reportage and opinions can be better-informed than those of the man in the pub.
Without that knowledge, skill and determination to find out what's really going on, the people in power would behave a lot worse. And I'm not just talking about politicians.
So we all need to think a lot harder about what we value. And if you value the news, analysis and opinion produced by expert journalists that you read every day in your newspaper, please buy it, or sign up for an app.
For if you don't, the price of free is that, in a decade's time, informed journalism may cease to exist.