Brief Wondrous Life... - Footnotes

Díaz, in the voice of the narrator, often employs footnotes to explain the history or context of a certain passage or sentence in the main text. Why do you think he chose to convey historical facts and anecdotes in footnote form? How would the novel have read differently if the content of the footnotes had been integrated into the main text? What if the footnotes (and the information in them) had been eliminated altogether?