A sales proposal is a document submitted by a seller to a prospective buyer that outlines the product or service being sold, its cost and associated terms of the sale. It’s essentially a formalized expression of an offer from one party to another. A sales proposal should be engaging and persuasive yet backed up with facts. It should also include specifics about any bonuses, discounts or incentives offered, as well as payment policies and any other unique benefits attached to the offer. Sales proposals are essential in helping buyers understand the details of the deal so that they can make informed decisions.