Is the profit earned from renting a virtual robot that markets and advertises products for major companies, and sharing the resulting sales commission between the renter and the robot, considered halal or haram, especially given the absence of any possibility of loss and the retrieval of capital with interest?

The aforementioned transaction, which involves paying a sum of money in exchange for owning the benefit of a marketing robot, with a guarantee of refunding the paid amount and taking a percentage of the marketing profits, is not valid as an ijarah (definition) (lease/rental contract) because the lessee owns the benefit, and the profits should entirely belong to them.

Nor is it valid as a mudarabah (definition) (profit-sharing partnership) because a partnership does not permit guaranteeing the capital, and because there is no significant work from the capital owner that would entitle them to a profit.

In summary, this transaction is a stratagem for riba (usury/interest), as it involves taking an increase on the paid money while guaranteeing the principal.

The correct form of ijarah is for the program to be yours in exchange for a specified rental fee, and all profits to be yours without any participation from the company, while ensuring the reality of the marketing and profits.