From the Database Administrators Area 51 page it says that there are 132 visits/day, but the site itself lists 991 visitors/day in the Site Stats. It would seem that visits/day would be higher than visitors/day. The visits/day on Area 51 was zero before the public beta started, which was understandable (and appears common), but it seems like it should be higher now. Should we assume these stats are not accurate until the evaluation wording is added (Excellent, Okay, Worrying)?
The Area 51 page is using the median over the last 14 days. This site hasn't been in existence for 14 days, so there are a few days with a value of 0 that are bringing down the numbers a significant.
Now, a site's views_per_day is calculated as follows:
Vn = sum of view counts of all questions created after the site (regardless of where they were created originally)
F(q) = (q's view count) * (number of days the site has existed) / (number of days q has existed)
Vu = sum of F(q) for all questions created before the site
views_per_day = (Vn + Vu) / (number of days the site has existed)