I bought my ticket from PHL-FLL on Sunday - with connections in PIT. So, they were definitely sold out before this business week started. Plus, I am sure FLL is a popular warm weather destination, as I visit my condo there more often in the winter. Oh well, an additional 1000 miles (PHL-PIT, PIT-PHL) doesn't hurt.
P.S. I remember buying tix in Nov. for a couple of RTs PHL-FLL at $78! Bought those a few days before the 20th anniv. promo.