xBlog plugins are controlled by session parameters by default.
This will keep in mind the state of each xBlog plugin. For example:
A visitor can leave a page with three xBlogs (one with paging on page 6, one with a single view). If the visitor comes back, the xBlogs will display the last selection (here: one with paging on page 6, one with a single view).
user friendly guided tours
short URI in a lot of cases
You can disable the session management by the extension manager.