Long proposals will probably be set aside, indefinitely. Manufacturers are more likely to respond to an individual than a marketing company. Over the years some of these manufacturers have received hundreds, even thousands of submissions from marketing companies. Many of the submissions are unrelated to their business. Our clients have told us they have received responses from the same manufacturer that ignored their idea when it was previously submitted by a marketing company.
Many marketing companies charge thousands of dollars to send letters to manufacturers.
These letters are usually mailed out over a one or two year period to create the illusion that they are constantly working for you. In reality, they are working off prepared lists contacting a few companies at a time. Your invention will never have more protection than it has now. It is important to expose your idea to as many manufacturers as soon as possible. The longer the protection, the more value your invention has to a manufacturer.