TABLE 4.

Social media recruitment costs and outcomes.

Country	Cost (£)	Reach	Clicks	n
United States	212	6940	25	11
Germany	143	6168	32	9
Norway	127	3362	26	74
Spain	85	8700	39	5
Chile	85	112,400	875	241
United Kingdom	170	7554	32	7
Canada	127	5930	32	22
India	85	189,100	572	12

“Reach” is Facebook’s estimate of the number of people the ad was shown to. “Clicks” refers to the number of times people clicked on the link in the advertisement. “n” represents the number of participants recruited from each of the countries in which we advertised. Not all participants are shown in this table because some participants were recruited without social media advertising and some of these participants could have been recruited by other means as well.