Douglas Pucci (@SonoftheBronx Twitter) has posted ratings for the Season 1 Skin Wars marathon, which aired Saturday, June 6th. All episodes went in order.
5:00pm: 425K (+29%)
6:00pm: 404K (-5%)
7:00pm: 370K (-8%)
8:00pm: 294K (-21%)
9:00pm: 248K (-16%)
10:00pm: 314K (+21%)
11:00pm: 253K (-19%)
Eight-hour average: 326,000 total viewers
Primetime average (8-11pm): 285,000 total viewers
Overall, solid numbers for a show that doesn't rerun well (since viewers know the outcome of the season).