I often use Flickr and YouTube for hosting my lens images and video and as a way to drive traffic. I prefer hosting my best-looking photos on Flickr as opposed to Photobucket or even my own website, because I can add something in the description field like “This is an illustration for Ancient Greece Odyssey: My Tour of Delphi” which gets keywords into the link. Having tagged my photos carefully for things like Greece and Delphi and Greek Art, I get a lot of traffic from people searching for those iamges on Flickr.
These are the kind of visitors you want most: a targeted audience who will be more likely to click your links, or even your sales modules, because they’re interested in what your lens is about.