If you read, and as a writer I know you do, you've no doubt come across various statistics as to the information we're deluged with on a daily basis -- even on a per second basis.
But, our brains, tireless filters that they are, sift through all that info at incredible speeds pulling out what we need to know from what we can, with little or no consequence, put side and ignore. With that in mind and these statistics reverberating through our thought processes, that same article pointed out that 99.9 percent of all that incoming information is instantly tossed aside.
Hmmm, that gives you, the writer, a .1 percent chance of your information making it through the filter. Not very good odds.
Now, don't panic. The reader is there because he or she wants to be and so is happy to be absorbing the information the writer is presenting - that's you.
But, and it's a big BUT, that doesn't give you license to bore or overload your reader. Those readers are still wired to filter out the extraneous material. So, that means you, as the writer, must introduce things the reader needs to know. In fact, in this situation the reader is assuming that everything the writer tells him or her is something he or she needs to know. And that means that if, while you're writing, you add words for the sake of adding them, if you provide pointless information your reader is going to read meaning into it, even if you were typing empty words. And that being the case, the reader will read the wrong meaning into those written words since there can't be a right one if you're just pumping out 'background' that doesn't relate to the story other than to fill space.
Okay, that's bad. So, the solution?
You've heard it before.
Kill your darlings. Do it with enthusiasm.
Write tight and learn to recognize when you've gotten a bit carried away and, while the writing may be great, have created a whole spiel that's unrelated to your story and keeping it on track.
Think about it. Provide what your readers need to know and you'll keep them hooked through your book.