Product Messaging
Product messaging is a document that involves feature and benefit description of what the product does and contains data related to the value the buyer would get by buying. It is to be used as a marketing tool and would most likely be available through a data sheet.
At an SVPMA workshop, the difference between product messaging and sales messaging was illustrated by Michael Cannon of the Silver Bullet Group.
While Product messaging is product-centric, sales messaging is more of a sales tool in that it is more persuasive by answering questions for a customer like "Why Buy?" and "Why Buy from you?".
The persuasive nature of sales messaging can actually benefit a good product marketing document as well. By preparing three to five reasons why the buyer should choose your product over the competitions, you are consciously evaluating your own products (new and old) and also thinking of extensions to existing products.