I have had other business that were 100% internet based in the past and the search engines like Google, Yahoo etc all change the listing criteria every few months and even weekly if they are not happy with what they see. They say to givea chance to everyone. I always got the feeling it was to force more paid listings to stay on top. From what I have learned hosting can be a isssue but very unlikely and if a host has hundereds of photographers that would be an advantage, just like links to your site from others in the same business are good to have. More to do with file names, meta tags, word counts ( too many or too few), flash or non flash and the value given each area.