Alex St John has good details on why using existing epidemiologically formulas don't work: http://www.alexstjohn.com/WP/2014/01/23/forecasting-demise-facebook/

Alex St John has good details on why using existing epidemiologically formulas don't work: http://www.alexstjohn.com/WP/2014/01/23/forecasting-demise-facebook/ http://www.alexstjohn.com/WP/2014/01/23/forecasting-demise-f... Example: "The amount of time you spend sick with the flu is constant no matter how many of your friends ALSO contract the flu"