The economics of in-flight wifi assume that no more than a handfull of passengers are using the system, otherwise connectivity just gets jammed. By charging, you create the scarcity that makes such a system viable.<p>By offering it free, you potentially make it available to no-one as suddenly everyone who has a laptop (prob most people flying in/out of SFO for example) is going to want to get on.<p>If I was taking a cross-country flight this holiday, I'd rather the system stayed for $$ so that I knew that I had a chance to get access to a usable system rather than turn up for my flight expecting connectivity and end up bored and disappointed because I can't get any bandwidth.