Large shops generally have in-house expertise so that issues can be resolved ASAP. What they paid Red Hat to do is provide a level of quality in the OS distrib

Large shops generally have in-house expertise so that issues can be resolved ASAP. What they paid Red Hat to do is provide a level of quality in the OS distribution and support in the (unlikely, in your case) event that an exceptional issue was encountered. Sometimes it's cheaper to pay that fee so you don't have to worry about any licensing issues in the future. And even though the you're saying it was a "substantial" amount, it was most likely considerably less than the possible alternatives (especially if you're considering other UNIXes like AIX and HP-UX that also involve specific vendor hardware). The GPL license isn't as big, bad and mysterious as it was previously perceived to be. A lot of that was due to the unfamiliarity in the early days of Linux (and Red Hat) and a whole lot of FUD that was being spread by the likes of Microsoft. While actual legal precedents aren't quite there (cases being settled, etc.), there's currently enough of a track record that it's pretty clear when you can or can't use GPL software. A BSD-style license is pretty clear that you can use it for commercial purposes.