Great article I read some time ago (and only just recently rediscovered) re: the awful truth when it comes to who, exactly, is reading your screenplay (that oh-so-precious masterpiece that you spent months, nay years slaving away over) and HOW, exactly, they're reading it... For more about said awful truth, I bid you: read on--
Screenwriters have funny ideas about readers. Some view us as malevolent fire-breathing trolls who get out the long knives before turning a page. The funniest misconception is the equivalent of an urban myth, still circulating among pre-pros, that readers "don't even bother to read the whole thing."
If only! Story analysts have to read each script from first page to last, even when it's obvious from Page One that it's a godawful travesty, because - and this is often the dirtiest part of the Dirty Job That Someone Has to Do - we have to write a synopsis.
Reader mean-spiritedness, when it really exists, is largely a reaction to this grunt-work. There are few things more aggravating to a reader/writer than having to speedily synopsize a poorly plotted piece of work (sci-fi/fantasy specs are the most horrific of these, since trying to understand, let alone explain story developments in an incoherent interplanetary saga can really crash your hard-drive).
Then comes the more involving task of writing comments that annotate the pros and cons of the material, but here's the awful truth that a pre-pro screenwriter ought to know about coverage. The problem isn't that the reader doesn't read your entire script - he's often the only person who does. No, the problem is that the executives we work for rarely read the entire coverage. They may not even read a word of it, before pronouncing your 2-3 years of work to be D.O.A. Their interest is often entirely predicated on a visual.
Allow me to introduce to you (cue drum roll) the grid.
The grid (aka The Box) is the alpha and omega of script coverage. Specifics vary, vis-a-vis the terms used on the left-hand side, but this one is typical. And the arrangement of "X" marks across those lines is sometimes all a buyer needs to look at before dismissing a submission.
To be fair, the 1-2 sentence log-line (summary of the concept and basic story thrust) that appears on the cover sheet with the grid is usually just as important. Of secondary importance is the Comments Summary (1-2 sentences) that follows the log-line.
I usually cover 8-9 scripts a week (the average is two a day). How often do marks enter the "Excellent" column? Maybe once or twice a year. How often am I X-ing into "Poor?" At least 2-3 times a week. About half the spec scripts one reads earn a box score like this:
Now here comes the truly abhorrent truth: the most important line is the first one. High marks for characterization and dialogue can serve a writer well (i.e. even if the script doesn't sell, the reader may recommend that writer for a studio assignment). Poor Story/Structure marks can give a buyer pause, and high ones will definitely help; same goes for Setting/Production Values. But solid "Good" for Premise (aka Story Concept)? If the log-line appeals, the exec may read the coverage. She may even read the script.