There are online article writers on Hubpages, Associated content, Ezine, etc. with 10 million page views (Details of 10 million authors ). Even on Knol there is one author now with 5 million page views and in a year's time, he will reach 10 million page views. There are some more authors who will reach such milestones on Knol. I am presently having 35,000 page views and some time back, the number could be 50,000 page views. The number is likely to increase as the Knol platform becomes more popular and authors support each other more.
So there is scope for online writing even now. Especially when the area of writing is areas where online content is sparse, the chance of success increases significantly.