These are good points you have here David but I'm not quite sure of all your meaning, whether this subscription would be an optional or mandatory choice. A subscription-based recurring fee that entitles use of the product or services for a specified time period then stops working if it is not paid for or an optional choice to select this subscription service and the product still works regardless.
On the other hand, I would not be in favor of a timed-out subscription product that doesn't require constant updating such as AV software. I think being a "renter" providing constant cash flow to the company could lesson their incentive to develop upgrades.
Granted, a product that would have most all the bugs worked out before a major version release would lesson the chance of feeling short-changed when paying for an upgrade. The company will have to be accountable for what they dish out to their customers. I don't mind paying for an upgrade if there have been substantial features or improvements made but only as an option. If the upgrades are good then the company will prosper. :smiley2: