A new software product comes along, delivers killer features that we never knew we needed but soon can't live without. A few versions later, there are a few new ideas, but mostly it's polish of the original product. By this time, most users can already do all they ever want to do, or are likely to want to do with it, but are persuaded to buy the updates due to either a) threatened 'lack of support', or b) clever marketing that persuades them that they really do need some trivial but exciting-sounding feature that's new in version 6.35 or whatever. If you're really unlucky, the product will be given a 'makeover' to make well-loved features more difficult to use in the interests of a pretty interface. Eventually, the market gets savvy and realises that there's actually nothing useful being added, and users start hanging on to old versions, 'risking it' with lack of support. Perfectly usable versions of the software from more innocent times and unencumbered by new fangled internet server-based licenses can live on for years. At this point, it's time to move to a subscription model...
R3