Copywriter Needed

I need an experienced copywriter to write 500 articles on different subjects. The aim of all the articles is to do pre-sell for some ebooks. For every article I'll give you the keyword that should appear 13 times in the article. The article should give a real value for what the reader looking for (the keyword), and lead him to our solution. Thus you also have to learn the benefits and the advantages of the product. The articles must be written in fluent English, without any grammar and spelling errors. You should have excellent English and good writing and copywriting skills. You'll have to write them in your own words and make them unique. All the articles must pass Copyscape 100% - NO plagarism allowed.