There is a lot of nice artwork featured on this website, and unlike some art websites such as DeviantArt, this one does not allow just anyone to sign up, and post artwork. In order for one to get a membership, they have to actually receive an invitation from a current member, which is a great way to ensure that only the highest quality possible artwork is featured on the site. Not that everyone on there is amazing, but at least you don't have complete amateurs posting whatever they feel like.
The main reason why I enjoy this website, and felt it was worth posting for others to see, is that it's a great source for inspiration when creating artwork. It's a really good way to see what other designers are currently putting out, not necessarily to copy them, but to at least be aware of what others in the field are doing.
