Though the term "profit" (Hebrew yitron) is used only six times in Ecclesiastes, its placement at the beginning of the book adds to its weight. It is used as if Solomon is asking, "In light of the fact that so much of life is vanity, is life really worth living? Is it worth going through life's vanity-packed challenges? What does one gain from it?"
Undoubtedly, life requires a person to expend a great deal of time, energy, and stressful uncertainty, companions of the pains of vanity. On the surface, life appears to be just running in circles, so what does one gain from it? Because of questions like this, Solomon takes the reader through the descriptions of the repetitious cycles of earthly systems that follow. Meditations of this sort make an individual appear so puny against the backdrop of the immensity of time, the earth's large population, and the monotony of the earth's natural cycles. The reality is that each of us truly is insignificant against such a background.
It is helpful to understand that Solomon's question regarding profit is asked in a rhetorical sense to stimulate thinking at this stage of his writing. Solomon already knows the final answer, but he is attempting to get his hearers to think along with him. As we study this book, we will find that not everyone's life is sheer vanity. Solomon finds that much of life is profitable but not truly lasting. On the other hand, if another factor is added to a person's life, life is not only very profitable because it is pleasing to God, but thoroughly enjoyable and everlasting as well.
John W. Ritenbaugh
Ecclesiastes and Christian Living (Part One)