Is it best that the gospel only be according to the lecturer?

I teach two sections of "lecture" Intro Psychology and two sections of "online" Intro Psychology. Why should I ever lecture if students could simply read the book? That's the question posed in this blog post, Why Are We Here? (In A Big Lecture, That Is), by a UC Berkeley economist. He argues the history of the university lecture stems from back when books could not be easily copied, and thus it was more cost efficient for a lecturer to read to a group. Students would take notes, because they'd never ever see the book that was being read to them. Notes were required.

Nowadays, of course, people can buy and read books themselves, and any lecture notes can be provided. Students don't need to take notes, but do they even need a lecture, what with the book available and all? The authors poses four possible reasons for the continued existence of lectures, I think the most interesting being that lectures are:

A sociological event: East African Plains Apes like to do things in groups that involve language--that is just who we are--and the lecture is just another example of this

Though I hate to mix human origin metaphors, an interesting comparison is that between the university lecture and the church (or other religious building) sermon. In both cases, books can be bought - assigned textbook or (for example) bibles. Yet, in both cases, people seem to prefer the person in the front of the room talking about the book rather than they themselves reading the book. If indeed that comparison is at all accurate (and I'm not confident it is), it shines a potentially harsh light on both lecture and book reading. Consider that "Americans are among the world's most 'Bible-literate' people" while simultaneously "(t)he Christian body in America is immersed in a crisis of biblical illiteracy".

I wonder if that, periodically in both instances of the university lecture and the religious sermon, the lecturer would prefer the person not read the associated book at all, but only hear what the lecturer says. Now to mixing faiths, take for example the semi-recent declaration by Imam Muhammad Adam El-Sheikh, co-founder and chief cleric at the Dar Al Hijrah mosque in Falls Church, Va. that "Beheadings are not mentioned in the Koran at all." That makes for a pretty decent lecture topic. But it doesn't quite mesh with the book the students might choose to read instead of attending lecture:

When you meet the unbelievers in the battlefield strike off their heads. (The Koran, Sura 47, Verse 4)

Likely, different people learn better from different sources. Books for some, lectures for others, still other sources for others. Perhaps it is the lectures and the books that should be of interest, instead.