"It's what on the inside that counts"...
But is this statement true? I'll admit that before I read anything I take in the immediate visual statement of it, wether that be a cover or the background on a web page. Honestly I think that the first glance at any reading greatly affects how the reader reacts.
Just imagine you're handed 2 documents. 1 a standard MLA typed 4 page essay, and a printout of a colorful blog entry containing the same information. I think that if you were forced to read both that most people would drudge through the black and white copy and take in a lot more of the colorful counterpart. I feel that this is a big reason why elementary and even secondary education text books are often littered with colors and pictures to try and pull the student into them.
I think that if a document is more visually stimulating it automatically seems more interesting because of the spectrum of visual aspects that can be used. Using C.R.A.P. effectively can both make your document look more interesting and actually may help the reader maintain more information.