Is Web 2.0 making information less accessible?

I recently learned that an excerpt from an upcoming book I'm looking forward to is only available through an iphone app. Despite the fact that it's promotional material trying to make me want to buy the book, it isn't on the internet anywhere. And because it's specifically an iphone app, people who don't have an iphone, ipad, or ipod touch can't get it at all. (I tried installing the app on my ipod touch, but it turns out the preview is available only the US, which is a whole nother rant.)

When Eddie Izzard first started his last US tour in 2008, I could do a google blog search the day after each show and find multiple reviews of each gig, or at least what he was wearing and which wikipedia entry he looked up. By the time he got to Canada in 2010, internet trends had moved away from blogs more towards Facebook and Twitter, so you couldn't necessarily find comments on any given show. They were all buried in people's Facebook walls, ungoogleable to the outside world. Not the most important thing in the world, obviously, but it was information I was looking for and could no longer find.

Blogger blogs, like mine, are very googleable. As a result, I get a lot of hits from people googling about things like the difference between La Senza and Victoria's Secret bras or how I connected my computer to my monitor. These things are helpful to people, and they wouldn't be able to find them and benefit from what I've learned if I'd posted my discoveries on a Facebook wall or Twitter feed instead.

One of the most egregious misuses of Facebook is promotional pages (either commercial or activism) that require you to join or "like" them (or whatever they're calling it now) to access the content. Apart from its inherent ridiculousness (if you don't let me see the information about why your group is of interest to me, I'm never going to join it), it renders information completely inaccessible (and ungoogleable) to casual passers-by, especially as more and more organizations move towards Facebook as their primary/only web presence. On top of that, my employer (and a number of others, I understand) blocks access to Facebook from office computers. So if I'm translating about an organization and I need information about them, I can't get at it.

I totally understand why you might want to keep your online presence limited to a select group of people, but I'm worried that as more user-created information is put on friends-locked walls or in ungoogleable apps, we might be not only losing access to existing information, but losing the ability to determine what information exists. Even though Google can't access all existing information, it can almost always confirm that the information exists somewhere I just can't get at straight through the internet. For example, the existence of academic papers has been googleable every time I've looked, even if I have to go through a library to get them. What if we lose this ability?