A. Ask the Product Owner to implement the feature anyway since it will close a deal.

B. Reach out to Developers who you think may support your position, in the hope of gaining more support for the idea.

C. Support the Product Owner's decision to focus on broader market needs in the long run, even though it may mean loss of short-term business.

D. Lobby other stakeholders to express support for adding the feature, to put more pressure on the Product Owner.