Sell the function, not the product, because circular revenue models can reward performance instead of volume. When a company remains responsible for function, it has a stronger incentive to design for durability, repair and efficient use.
In the circular manufacturing work, this principle connects business model and product design. Leasing, pay-per-use and performance contracts can keep ownership, data and end-of-life responsibility closer to the producer. That makes value retention easier to organise and reduces the pressure to sell more units.