I was in a committee meeting where a consultant came to help our group with a strategic planning exercise. Of the 90 minutes allocated to this activity, the consultant used the first 30 minutes to talk about all the great work she had done for other clients, the next 30 to show her expertise by expounding upon general trends in our market, and the final 30 minutes leading the group in the actual exercise ... the work she had already been hired to do.
Consider another scenario. You order a product and when the package arrives, you eagerly open the box, looking for the instruction sheet or manual so you can begin assembly or use. But this valuable information is buried under flyers, a cover letter, another copy of the product brochure, perhaps even sales materials for other products or companies. If it's a software product, starting the installation procedure may display even more lists of features and benefits, testimonials from happy users, and other promotional text.
"Enough already," you grumble. "Just let me get on with it!"
As these examples show, there is a time for selling and a time for delivering and supporting. And the same flow from selling to delivering should be represented in your marketing materials.
Yes, it is fine to use part of a white paper to showcase the expertise of your company or the credentials of the paper's author. It's fine for a letter or screen display to present a thank you message and to reinforce the customer's purchase decision. It's also fine to promote service programs, user communities, accessory products, and other resources for customer support and loyalty.
But once a customer has purchased your technology product or technical service, they no longer need to be sold. You just need to get out of their way and let them discover the positive experience you have promised.