I suppose that if I'm looking up a quote from a journal article online, then I can just search for the term in the article. Good in theory, but half the time when I search for something on a Web page (using, for example, the "find on this page" feature), the search term doesn't appear. One is at the mercy of any number of things that I don't claim to understand. If I suspect that the search feature is not working properly, then I'll search for "the" or "and," and if the computer tells me "Search term not found," then I know that the search engine for that page is not working properly.
And what if it's not a direct quote, but the author is referring to a concept, though not necessarily by the exact name that the cited author uses? Then how is one to find it electronically among what might be thousands of words?
And why would it be so hard for a electronic book/page designer to put in faux numbers somehow so that a researcher could indeed look on a particular page for a concept? I think some forward-thinking designers do this.
Compared to Gutenberg, we're still pretty early in this e-publishing game. There are some quirks to be ironed out. But as a reader, I'd be a whole lot happier if I saw a citation that read something like:
Jim James, "Latinos/as and the Liberation Motif," Hispanic Theology Journal 4, no. 3 (December 2002): 36.