The topic has come up before in my interactions with people about my interest in reading comics, and that is why is it that I like comics. In terms of a concrete answer I don't really have one, though the explanation of vicarious escapism is not the one which immediately comes to mind. While I associate with the characters I don't often get this impulse to know "what is next?" In my mind that is one main reasons that I think of that people hang around comic book stores for hours (or at least from what I have observed.) When I think about comic book conventions I have the same general idea, that it is a place to buy and sell, talk the talk, and in the case of cosplayers to maybe even talk the talk for a day or two (admittedly I have never been to a comic book convention.)
My last trip to the library got me a copy of the above mentioned book which looks in detail at the history of the San Diego Com Con, in its roots with a gathering of 300 or so people to the tens of thousands who frequent the Convention now. While some parts of this book reaffirm some concepts that I have of the conventions themselves, this book also does a good job of describing two other interesting aspects of this giant meetup. The first is that it showcases a human side, well demonstrated here by the annual Heinlein blood drive, which before reading about I had never heard of before. The second and perhaps more important to the average comic fan is that amount by which comic cons are not just a collection of comic interests, but rather by which they shape the development of the medium itself. Many heads come together at such a place, and invariably with so much creative talent there is also bound to be a lot of ideas being flown among them, some of them for not, but some of them also for good.
In that sense, I would think that this book is quite an informative one, be it for the Comic Con devotee, or for those who avoid them. Either way this book highlights an interesting aspect of comic fandom and I would recommend it to all.