What is the Value of Free Information?

I was reading a blog recently about the value of free things. I thought this was an interesting blog because the questions the concept of free and whether we should give away free information.

A few years ago, I used to give away a lot of information on my free blog. In fact,I used to provide about 10% of the paid manual for free. When the manuals were 10 or 15 pages long,this ended up with a blog about a page long. When the manuals were much longer, say, 40 or 50 pages long, this ended up with a blog four or five pages long. I am sure they felt that I was giving away all the information that I had. In reality, I was only giving away about 5 or 10%. So the question was, ” how much do the readers value this free information?”
If you are disappointed with the amount of free information I give away, I understand. However, the information I have is valuable. Since that information has a value, I feel justified in giving away a very small amount for free, but allowing users to subscribe to a service that has all the information for a small charge.
My feeling, is that if you pay nothing for information, it is probably worth what you paid for. I often give information freely on the Vectorworks tech board and on the Vectorworks e-mail list. Recently, a user posted a question on the Vectorworks e-mail list. Only part of the information was given. The user then complained that the free information he received back was somehow substandard. Had the user posted the complete and full information we needed, I certainly could have given a better answer. However, what surprised me, was that the user complained that the free information should have been better. This has caused me to rethink my contributions to these areas.
There is a theory that says information should be freely given to anyone who needs it. The challenge I see with this, is that it does take me time to give that information to another person, and also took me time to learn that information. That means this information was not acquired freely, so why should it be given freely?