I've seen this done with an enterprise hardware firewall (can't remember the brand, probably Sonicwall.) It came supplied with an internal HDD fitted, but it required an optional license upgrade to active the internal HDD, e.g. allow storing of logs. The annoying thing in this is case is that I'm sure the cost of the HDD is somewhere in the original hardware cost, but obviously the HDD cannot be used unless the user chooses to pay the optional upgrade fee.
On the other hand, it's not that much different to hardware where there is a service/subscription charge to use its extra features or gain extra performance out of it.
Few other examples:
Sky+ PVR receiver (Ireland & UK). It will function fine as a FTA satellite receiver, but you must pay a subscription fee (I think Â£10/â‚¬15 per month) to enable the PVR capability without availing of any Pay TV channels. What's worse here is that unlike what Michael mentioned above, it's not a one-time fee. If if you cancel the subscription, you lose the PVR capability.
PCs - Assuming your PC is running Windows, you've already paid a fair percentage of your PC cost to Microsoft. The costs become obvious if you try building your own PC, assuming you don't go the Linux route.
Mobile phone, Electric heaters, Water filters, etc. - The more you use them the more you pay.
HD Cable/Satellite receiver (most countries) - You pay a HD subscription fee just to get the subscription channels in HD.
Television (some countries) - You have to pay an annual license to have one. In this case the license fee doesn't unlock anything special, but you don't want to be caught with a TV without a license. :disagree: