The difference is that the value of one instance of ad engagement (yours) is lower than the cost of a packet of rice. But the value of thousands of engagements

The difference is that the value of one instance of ad engagement (yours) is lower than the cost of a packet of rice. But the value of thousands of engagements (number of readers) is higher than the cost of producing an article. Distributing articles over the internet scales better than distributing rice packets through stores.