Most likely that figure on daily basis is under influence of the number of robots [bots, crawlers, spiders] visiting the board, which can swing wildly. [sanjeev might however have shut the bots out]. Bots can be good or bad. We as Internet users need the good bots, because they constantly read and map the ever expanding frontier of the Internet, thereby making the internet searchable.
I.e. about the GoogleBot here:
http://en.wikipedia.org/wiki/Googlebot
https://support.google.com/webmasters/answer/182072?hl=en
Bad bots can have several questionable purposes, among them harvesting email adresses for spam purposes. On this board [a SMF board], the bots aren't visible. I don't know if Sanjeev can make them visible. On certain other types of board software the administrator can make bots visible, i.e. please take a look at the homeplace of an other board software called phpBB [ https://www.phpbb.com/community/ ], where you can actually see the names of the bots visiting that board recently.