dotbot is one of the data sources that SEOmoz uses for their Linkscape crawler. Not sure why it was submitted here but I suspect promotional motives.
It is interesting data, but when people build crawlers to index the entire www, especially if the data is intended as an SEO intelligence tool, certain issues arise. Some background on this particular issue: http://incredibill.blogspot.com/2008/10/seomozs-new-linkscap...