Looking at just the loads of the flights really tell you nothing about whether it's making money of not. You have to look at what type of fare they paid. Just like those Florida flights, it's always 100% full during peak season but chances are many people paid the lowest fare so you're making very little (if any) money on them.
If you start to set a trend to let people buy fares at the last minute at a deeply discounted price regardless of day of the week, then a lot of people would just wait til then to get their tickets instead of being 'forced' to buy the higher fares because there's no Sat night involved.
The current websaver fares are way too high for a last minute weekend getaway. I don't think you'll find many takers.
[This message has been edited by Empress (edited Nov 14, 2003).]