Site ranking in the Galaxy directory

how are the sites ranked?

[Spica]

I noticed that the Galaxy directory lists sites by rank (little blue and white bar at left). How is this rank determined? Does anyone here know?

[cornwall]

I took a look at their site rating. Seems they are all a multiple of 7, though I have no idea why ( a touch of Douglas Adams maybe)

A cross section of my sites seemed to rank well on Galaxy, but I get little traffic from them.

Their own traffic is low, if you look at the window with their live on-line searches, its only 7 or 8 a minute when I was looking. Say 500 an hour