With the writing of original content becoming a more important aspect of website promotion there are now millions of writers online. There is a big difference between writing sales copy and normal every day writing and the text communications seen on Facebook and Twitter.
There is a big difference between Copywriting and article writing. The copywriter is selecting specific words in a specific order to entice the target market that might be on a website for only ten or twenty seconds. Normal article writing is completely different and is certainly not as 'artistic' as simple content creation.
100% completely original content can also be very specific to a target market as well, despite the fact that many different websites selling original content offer generic original content. Although I also like to write longer dissertations like 2000 word or more I will gladly write a 500 word article for only $5.