What is the ruling on subscribing to internet companies that require selling subscriptions to others in order to earn money?

If the company allows it, you may share the service with others, whether for a fee or not, unless it is known that they will use it for something forbidden. However, if the company does not allow it, then you may not share the service with others, as it is obligatory to fulfill the terms of the contract, for the Prophet, peace and blessings be upon him, said: "Muslims are bound by their conditions."