Discovered Artists.com
Our mission: Original art for every man.
Fine Art America
Get my prints on demand.
Mixture
A contemporary home furnishings and accessories store, 2210 Kettner Blvd, San Diego. 
Artchain
Artchain provides a searchable directory of artists, art guilds, galleries, and art groups throughout  the United States and Canada.
Art*o*mat
Art*o*mat machines are retired cigarette machines that have been converted to vend art. There are 82 active machines in various locations throughout the country. All machines are sponsored by arts organizations and/or individual patrons of the arts who share the vision of bringing the work of living artists to their communities.
Etsy Store
I sell ACEO cards and small format art. My ID on the site is, "greyocean".
Ebay
ACEO trading cards and small format art for sale. My ID on this site is,"bradleyabstractart".
Saatchi Gallery
Online art gallery from the UK