Fastbot term explained
The search engine robot, after coming to the website page of which result instantly appears in the results on a number of key queries.
Fastbot usually goes on frequently updated sites, news sources or any other materials. Blogs and other resources, having an RSS feed will also be processed by fastbot.
Fastbot into account only the internal factors of the page in order to rank it in SERP, so, usually, the position of the site on key word change after the arrival of the main indexing robot search engines.