Not even a comparison such as 400 gigs of bandwidth is equivalent to a company of X size/ brand recognition and would be operated by Y number of employees.
Well, thats around 500 times larger than the
Cambridge Accommodation Notice Board, which takes me a few minutes per day to maintain (just the site, that is, the ISP maintains the server) and gets around 2,500 visits per week. So that would put PPRuNe at maybe 125 hours per day, split across all the moderators, and 1,250,000 visits per week. I suspect somehow that these numbers don't really scale like this.
[Edited to correct arithmetic.]