Personal art portfolio or online gallery

Just came across this discussion at EmptyEasel.com. At question is the matter of building your own web site to showcase your work or using an online art selling site. I don't think it's an either/or question, but it points to the missing element in the online art world (the topic of this blog in fact), which is that there is a value in building your own web portfolio and *also* in using an online art seller. The fact that there is debate on this topic illustrates a niche waiting to be filled: the site that delivers all of the customizeability and context of a personal site, with the traffic and selling tools of an online art seller.