Several of the traffic sources have an identical number of page referrals. I think that this is way too lucky a coincidence since 6 sites have 258, 2 have 516, 3 have 773. What is going on here?
From our Site Analytics:
There is some sampling process involved in the determination of these numbers, as Jon Ericson said.
The numbers are sampled so it's not uncommon to see implausible results such as several search engines at 211 visits.
For sites with small referral counts this means the data don't say much other than "their number of referrals is pretty small".