If you plan to sell your art online with your own unique website, my advice is simple: Be Different! There are hundreds of artist websites online today that are all making the same mistakes.
The first problem I would like to note, is the use of long multimedia presentations that artists are incorporating into their websites. I don’t think there is anything more frustrating then arriving at a website and waiting for this huge multimedia presentation to download and play. The artist may think it’s cool or adds something to their work, but in all actuality, it only frustrates impatient surfers. Not all Internet users have super fast cable or DSL connections. Many are still using dial up modems and if they have to wait for something to download, they will simply leave and visit your competition.
There are also sites that insist on putting unrelated banner ads or other unrelated advertising on their websites. Just the other day I was doing a search for original watercolor art. The first website I arrived at had a big banner at the top of the website advertising a dating site. I am not sure how dating is related to watercolors? This is simply a distraction...