Before revision:  Outside groups ran 62\% of Facebook ads, with dark money ads outnumbering ads with more transparent campaign financing (3:2). A majority of ads (63\%) were microtargeted to less than 1000 Facebook users. Outside groups used microtargeting to run ads that have more negative sentiment, and candidates and parties used it to run ads with more positive sentiment .
After revision:  Outside groups as a whole also ran more negative ads than candidates and parties used it to run ads with more positive sentiment .