Software is a peculiair product. Take a look at commercial software, you pay a licence fee and on top of that support & maintenance. Support & maintenance (S&M) in some cases is only to be paid the first year after you acquired the right to use the software. However most commercial software vendors require you to pay S&M right from day one. It seems S&M is kind of an insurance / warranty to have the right to upgrade to a new release and be able to log tickets in case there is a problem with the licensed product.
Kind of a strange system if you think about it. You buy the right to use an 'imperfect' product and right upfront are forced to pay for the warranty to have issues fixed, although you don't receive a garantuee issues will be fixed. In case a new version with less /different flaws is release the S&M gives the right to use the newer version of the software. Sofar so good, but the funny thing is that you have to pay S&M per licence and licence in many if not most cases are CPU based. A CPU based license has a huge TCO, both in acquiring licences and the S&M cost.
So why do you have to pay S&M per CPU, the software vendor fixing the flaw doesn't have to do more work whether the software runs on one or multiple CPU's. The number of issues / flaws don't multiple with the number of CPU's.
Someone might argue this model will be difficult to sustain simply because TCO is getting too high. The alternative being investigated is Open Source Software, where there is no licence fee and no support unless you specifically want it. Yet the right to upgrade to a new version is 'free'.
In case you an organisation doesn't feel confident running a software product without support they can opt for a supported open source model. Meaning you pay S&M on top of the Open Source Software product and sign a contract with the company / a company that is closely linked to the Open Source Software product.
No upfront licence fees and you only pay for support if you decide it is a must. The nice thing is that support for Open Source Software is in many cases server based and not CPU based.