I guess this is the aspect I don't understand. With a lifetime of twenty years, most software patents (a lot of hardware patents for that matter) cover the enti

I guess this is the aspect I don't understand. With a lifetime of twenty years, most software patents (a lot of hardware patents for that matter) cover the entire viable commercial lifetime of the product. In our brief experience of commercial software (what has it been? 40 years? Note: that's 2 patent terms) I can't think of very many software technologies that have lasted as a commercially viable product for 10 years let alone 20. To my limited understanding of how patents work and how the software market works I would think a patent term in the range of 1-5 years would be a lot more reasonable. It would allow for the patent holder to gain a competitively advantageous foothold in the market (the point of having a patent) and it would destroy the incentive of inventors to sell their patents rather than creating business from them. I'd be interested to hear from people with more knowledge of these subjects than me as to why this isn't the way software patents are maintained.