You can decide whether to give away or sell the reports you write. I prefer to give mine away for a few different reasons. The main reason is that many more people will be able to read my reports if I make them available at no cost. These readers are also more likely to give them away to others who they know. The result is that my short report ends up in the hands of people who would otherwise never have connected with me. That is the beginning of viral marketing, especially if what you write in your report is considered good enough to share. 

Keep in mind that you will want to focus on a narrow topic in your report. Instead of writing about an overall general topic, keep it niched down so that it is more specific. This will establish your credibility as a specialist in this area, and make both you and your information more sought after in the marketplace. Include some affiliate links in your report, and make sure they are appropriate to what you are writing about. This is one way that you will earn income from your writing for years to come. No more than one affiliate link per page is a good rule of thumb with this. 

Also be sure that your contact information is on each page. Imagine someone printing out your report and giving it to a friend. Then, imagine that person dropping it on the floor and picking up a few pages later on, maybe even months from now. If they do not have your name, website, and other information, they will never be able to connect with you. This is simple enough to include in your footer and header. Do the research you need in order to include as much valuable information as possible in your short report. Most of mine tend to be about ten pages long, but yours should only be as long as is necessary to provide the information your prospect would need to understand your topic.