Truly, the issue isn't choosing between half a million books, because no reader is going to be interested in the subject matters of all those titles. The real challenge readers face is finding the titles that will most appeal to them in the genres and fields that interest them.

This is still a problem, and still a large problem… but it's not an insurmountable, hard-to-wrap-your-head-around-it's-so-big problem.

The issue is also a subjective one — one person's War and Peace is another person's Twilight — so that narrows the field even more. What it comes down to is the same thing it always has: finding reputable sources you trust to tell you what might be good to you.

Those sources have expanded with the advent of the Internet, but the means to sort and review the sources have improved, too.

It's the responsibility of the content creator (publisher and / or author) to understand who the audience is for a particular work, and where that audience is.

A huge number of books isn't the crazy thing. Expecting to reach a huge number of readers, and sell them each a copy of a particular book — that's where publishers and authors need a reality check.