Why This Will Work

Economics.

People don't like subscriptions. They don't like to be locked into recurring charges. As the economy tightens, we see people cut back, and the first thing they cut back on, if they are smart, are those silent monthly charges. If software vendors decide to go in the direction of subscription pricing, my guess is that they will prosper in good times and get pinched in hard times. I think this is basic economics and psychology at work.

The fundamental dynamic here is that people will always fear that they will not get enough for their money with a subscription. That is, they will always be concerned that their usage will be below average, and hence that they are funding (subsidizing) other "free riders" who use the service more at their implicit expense.

On the other hand, people are used to paying for batteries. Batteries are a consumable, and you pay for them according to how much energy you use. Use the device more, deplete your batteries more. No one complains about that. To most people, that seems fair.

To illustrate my point, look at the consumption of inkjet cartridges in low-cost color printers. These cartridges are relatively expensive, but the market tolerates this because they are viewed as a consumable. In fact, there are all sorts of after-market vendors whose existence attests to this basic usage model; their only function is to lower the unit cost.

So by putting the software into the batteries, you would transform it into a consumable that gets thrown away with the dead battery. You would factor the software cost into the price of the battery. Spread over many, many units, the added cost would be pretty low. Coupling software usage to battery usage might ultimately be the simplest algorithm we could ever devise for charging (no pun intended) for software based on a usage model.

Will people (electrically) recharge their software batteries? They could, assuming we have piggybacked our software onto rechargeable batteries. In this case, they would retain their old software, perhaps indefinitely. But it wouldn't invalidate the basic model. And someone could always upgrade their software, if they wanted to, by throwing away a perfectly "good" battery and replacing it with a newer one. Who knows, there might spring up a secondary market for "old" batteries that still hold a charge. Maybe there will be battery exchanges. I could ring up a lot of changes on the basic model. The important concept here is that the free market and its economics would drive things appropriately.