Whenever you are writing for the purpose of influencing other people (which pretty much includes all writing, doesn't it?), it's essential to know your strategic objective.
Strategy in this context means: the overall approach to achieving the outcome you want.
This may not be as simple as you think.
Even if you know your desired outcome is the sale of a product, you have only identified the target; that is not an answer to the question of strategy. The question of strategy is: how will I hit the target?
One possible strategy is: the creation of advocacy in the mind of your prospects. Let me explain.
The most straightforward product sale can be strongly influenced by first defining a position of advocacy you want the reader to adopt.
For instance: let's assume you sell a highly commoditized product, like machine screws. How on earth could advocacy for some position or other influence the purchase of machine screws? Well..
Perhaps you begin by realizing your company has a commitment to using only the finest quality materials in the manufacture of your machine screws. Perhaps you further realize that you have unusual attention to detail in your manufacturing facility, and that this grows from the quality philosophy of your business. Maybe you believe that a lack of such strong standards is one of the things that have contributed to our current economic woes.
In the above scenario, you might choose to write and publish an essay on the importance of high standards not only in the manufacturing process, but also as the foundation of success upon which our country was built.
You might even go so far as to suggest that the solution to the economic problems facing our country is rooted in a return to this kind of commitment to quality.
If you publish this essay (or blog post, or podcast, or brochure, newsletter, even postcard) in a place where your potential buyers will encounter it, and if it is written powerfully, you stand a good chance of influencing their buying decisions about machine screws without ever overtly writing about that particular subject.
Of course, before you can authentically write to persuade people to adopt a position of advocacy, you first have to possess such a position yourself.
A worthwhile question to ponder: what do you stand for, and how does that relate to the world of the people you wish to influence?
Changing behaviors of your audience can be merely temporary; changing mindsets is more permanent, and changes behaviors automatically.