This article goes into detail explaining what thin content is and why it is so harmful to your website. Thin content briefly is any page of your site with too little content or rambling content without keywords.
Duplicate content is also considered thin content. We all have some duplicate content on our sites. We have to balance giving our readers good, interesting content and making the search engines happy. However, writing this intro piece before linking you to the article puts keyword content on my site and shares the expert article.
We can all write original content however. We are the experts on our business! So figure out the keywords you want to rank for and write content using those words.
Review your pages. Make sure those words are used as often as possible. I’ve found the best method is write your content for the visitor. Then go back and insert the keywords where possible.