There’s a reason to make people pay for your work. While profitability would be nice, it’s not the main goal. People being willing to pay for your work suggests brand engagement; you’ve made something people want. It also encourages them to actually use the thing. Consider the Michelin Guide, one of the original pieces of so-called content marketing: 

To help motorists develop their trips – thereby boosting car and tyre sales and in turn – the Michelin brothers produced a small red guide filled with handy information for travellers, such as maps, information on how to change a tyre, where to fill up with fuel, and for the traveller in search of respite from the adventures of the day.

For two decades, all that information came at no cost. Until a fateful encounter that remains a favourite anecdote repeated today, when Andre Michelin arrived at a tyre shop to see his beloved guides being used to prop up a workbench. Based on the principle that “man only truly respects what he pays for”, a brand new MICHELIN Guide was launched in 1920 and sold for seven francs.

We all know where the Michelin Guide is now, compounded after decades of consistent effort. Consider more contemporary examples, like Stripe Press, and Cash by Cash App. If you do your marketing right, it doesn’t look like marketing.