The difference between a white paper that reports on a subject and one that sells a product is not always clear. A well written paper can do both. When reporting on a subject you want to list the issues and theories that are involved in that subject. The same can be done for a when you are selling a product. You want to list the issues that your audience has and possible solutions to those issues. Both types of white papers should site outside sources to support their writing, provide technical detail without loosing your audience, and communicate in a clear manner to your readers.