Sometimes if you get good enough at writing SEO you start considering doing it for a living. Be warned however --this is not a career for people who are perfectionist or who see it as a way to having a reputation as an expert advertising copywriter.
If you want to research the SEO writing market go to the big writing auction sites like Elance and Guru. This will give you a good idea of the low pay involved in such a career. You will also notice that the individuals with the least feedback and work on there are those that have the idea that they will be selling high quality writing on the Internet. This is not the market nowadays.
Lower priced writing that is done for cheap is what most business people on the Internet are willing to pay for. Most of them are likely to have less education then you and also have no real idea what great writing is. Great writing, which is what the mass majority of Americans, which have a Grade Four Reading level, can read. So this is not really the arena to start writing like Shakespeare.
For instance on Elance there are many writers from the United States stuck in off-line world prices for their work from 1988. You see them bidding for jobs at a dollar a word. However the going price is more like a cent a word and they have no idea that the market has changed to favor outsourcing from India. They have nothing to offer a client of value except for a resume dripping with obsolete education. Unfortunately what they teach you as an English major is not the skill set that you need to please the client who wants SEO articles done.
If you truly are a great talent then take yourself to an offline agency that may be able to place you in the right writing job for the right price. SEO writing is not for those who can’t tolerate mediocrity as often-bad grammar and misspelled words are actually part of achieving this type of content.