Selling your art can be a daunting task. There are so many of us on the web trying to do just that.
Unless you already have a following you will find it difficult to sell your work via the Internet.
There are websites where artists share their experience which might be of interest to those who are thinking of joining the fold. There is an ongoing discussion about the merits of the Internet for artists when you click on the following link.
It may also be interesting to browse through the comments on the following link where artists are discussing their views on what sells.