Regarding the footnotes in Infinite Jest, Wallace wrote to his editor:

“I’ve become intensely attached to this strategy and will fight w/ all 20 claws to preserve it. it allows me to make the primary-text an easier read while at once 1) allowing a discursive, authorial intrusive style w/ o Finneganizing the story, 2) mimic the information-flood and data-triage I expect’d be an even bigger part of US life 15 years hence, 3) have a lot more technical/ medical verisimilitude 4) allow/ make the reader go literally physically “back and forth” in a way that perhaps cutely mimics some of the story’s thematic concerns… 5) feel emotionally like I’m satisfying your request for compression of text without sacrificing enormous amounts of stuff”
(Every Love Story Is a Ghost Story 195-196).