The service isn't going to be provided for free -- it's a business, not a charity. One way or another, it gets paid for. You have two options:

• Pay with your data. That's what happens today. If someone's okay with that, it remains an option.

• Pay with money. This would be an option to the above.

Personally, while I don't use or care about Facebook, I'd like to have the option to pay with money rather than data for services that I do use. Some of those don't have that option today.

I'd also add that this doesn't just apply to online services. For example, we've been talking about car tracking using cell radios to send data back a bit on the Threadiverse. If someone doesn't care about their car transmitting data back, okay, fine. I've got no problem with that being an option available to them, if it can reduce the purchase price and someone is okay with that. But I'd prefer to have the option to just pay a higher purchase price and not have that happen. I don't really want to screw around with trying to game the system and disabling cell radios and trying to let other customers bear the price of my subsidized car (nor is that really fair to those customers, frankly). I just want to have the option to pay for my car the way I historically did -- I give money to the automaker up front, deal is done.

A vendor should be agnostic as to whether someone pays with data or money, as long as they are able to charge enough to cover whatever they lose via not being able to sell data and whatever overhead exists from maintaining two payment models. The only argument I can think of against it is that it requires them to expose some data as to how valuable they assess the data to be. That might be considered a trade secret, but given that the consumer really needs that data to assess whether-or-not they want the company to have that data and that price information is required to be available to the consumer for an efficient market to work, I'm okay with imposing that limitation on the vendor.