Hi Jim,
There are lots of reasons why you may not be getting any traffic to your site, is mostly going to be down to its visability on the internet.
Even if your imagery is poor (which I dont think it is), you would normally be receiving visits to your site even if they never return.
I did a quick search and can see hardly any sites linking to your website, you need to change this for starters. I would suggest adding signatures to any forums you use and submitting the site to all relevant search engines.
I have myself received over 1500 hits from a single (rather inflamatory) post on a gaming forum some time ago, it really does make a difference.
Facebook and other social networking sites are also great for getting your name out there, these account for about 80% of my traffic currently, so are well worth the effort even if you dont like social networking.
key tagging your images is also very important, but as someone still setting up my seo on zenfolio and cannot really give you feedback on how effective it is on zenfolio yet, but you should be able to type words relating to your images and have the search engines finding them. I used to have first page rankings on google images for pretty much all of my imagery about 18 months ago then switched to clickpic and lost all rankings and am yet to drag them back.
regular content updates and improvements are also essential, add content over time not all in one go. not sure how this helps but it does increase hits to your site especially if you are linking back to your website everywhere you go online.
you could also look at buying traffic to your site, it can help boost your rankings somewhat though its not going to guarantee you sales.
hope some of this helps
Henry