On one website I have, looking at the logs, I find lots and lots of "Sosospider" hits. Is this the same for everyone, or just me? Now, I have never once been sent any traffic from anything which looks like it might be anything to do with Sosospider, so can anyone explain what this thing does? Does it cache the pages and send cached pages to users or something?
It looks like it is just a search engine crawler for a website in China. The lack of traffic may have to do with the fact that your site is in English (assumption) and probably isn't what its users are looking for. I would think the crawler wouldn't crawl you since your site is not in Chinese (assumption) but maybe their system isn't that sophisticated or doesn't care.
Sosospider is a Chinese Search Engine. Whether you think it is worthy of crawling your site depends on your sites contents. My site is an online retail shop which does not ship to China, so we do not allow them to crawl it. However, if you decide to ban them and implement a robots.txt file, keep an eye on your logs because many have said they ignore the robots.txt (regardless of what their website states).