Human beings are pretty good, on the whole, about tradeoffs. For most people, the information they're trading away is only theoretically valuable, but the products they receive in return have very tangible value.
I'd see this as an argument why stuff like privacy can't be left to individual choice.
Also, if the product is really "invaluable" to you (e.g. you have no choice but to use it) then your choice to give up privacy wouldn't be voluntary either.
(Edit: added first paragraph)
I disagree with this assessment. What human beings are generally bad at is including the concerns of other people in their calculations. The probability that the information Google, Facebook, etc are gathering on them will ever be used to cause them significant harm is incredibly small. While one can imagine some future holocaust scenario enabled by it, no reasonable person would see that as likely from our current vantage point. The people affected by the way it is currently used, or the ways it is likely to be used in the future, are in a minuscule minority (and any competent authority wishing to abuse this information will no doubt endeavor to keep it that way).
> I'd see this as an argument why stuff like privacy can't be left to individual choice.
Is for your own good comrade!
(not to start an off-topic discussion about that, but just an observed parallell)