Does technical documentation have a marketing function?
Yes, it certainly does!
Some people think that marketing starts when you design your product. I happen to agree. If you have a great product, then your prospects will be attracted to it, and your clients will recommend your products to others.
A technical manual is part of the product. It represents your company in several ways:
A good manual is one of the easiest and cheapest ways of sending a potential customer a real part of your product for evaluation. A great manual helps sell your product.
After the sale, clients will have a lot of questions. The more sophisticated the product, the more this is true.
One of the main goals of a great technical manual is to anticipate all of the common questions, answer them, and make the answers easy to find. This is great for your customer, and great for reducing product support costs.
Technical marketing material is a more direct form of marketing. Examples include white papers and the copy on your website. This material explains your product to a technical audience, so they understand what your product does. It is also written in a way that shows off your product favorably.