Advisory work is "harder" to sell for several reasons. Actually, before I get to that, let me remove the quotes from the word harder. It really is harder for us because of the starting point we're all coming from. We're all some flavor of self-made expert, and we generally lack the bonafides and pedigree that would help us tell ourselves the confidence-building story that, "of course I should be selling advisory services!". We sneak our way into advisory services through some kind of side door without the institutional bonafides and pedigree, and as Alan Weiss says, the first sale is to ourselves.