I know for Bitcoin at least Cryptsy automatically includes a fee in excess of the minimum (0.0002 instead of 0.0001), it's probably the same for PTS.
From what I've been reading here, there are at least a few exchanges that send out PTS with 0 fee... probably because 99% of the time that's fine, since blocks come relatively quickly and it takes a while to reach that max block size for free transactions (10k for non-priority, 27k for priority? i keep getting stuff mixed up, so could be wrong). It's just on the 27th and 28th stuff got bogged down