Skip to main content
. 2021 Oct 13;23(10):e28923. doi: 10.2196/28923

Table 2.

Performance of digital recruitment ads.

Ad run dates Impressions, n Link clicks, n Cost ($) Study page contacts, n People screened, n People enrolled, n Cost per click ($) Cost per enrollee ($)a
Digital platform: Facebook

5/21/2019-6/26/2019 51,435 580 886.43 15 6 4 1.53 221.60

5/22/2019-6/26/2019 75,459 1033 1604.13 21 10 2 1.55 802.07

5/24/2019-6/26/2019 106,992 2011 1825.5 18 1 0 0.91 b

5/24/2019-6/26/2019 10,852 183 226.46 2 0 0 1.24

5/21/2019-6/30/2019 84,798 1118 1523.89 2 3 1 1.36 1523.89

5/24/2019-6/26/2019 33,767 373 537.28 16 3 1 1.44 537.28
Digital platform: Google

05/13/2019-06/03/2019 9473 291 964.42 3 1 1 3.31 964.42

05/13/2019-06/03/2019 876 23 50.59 2 0 0 2.20

Mean 46,706.50 701.50c 952.34 9.88 3 1.13 1.36d 846.52e

Total 373,652 5612 7618.70 79 24 9 N/Af N/A

aValues were calculated by dividing the cost by the number of enrollees for each ad. – indicated that no enrollee was recruited through this ad.

bNot available.

cMeans for clicks and engagement values were rounded off to the nearest whole number. Unless otherwise indicated, these were calculated by dividing by the total number of ads (n=8).

dThis value was calculated by dividing the total cost of the ads for both platforms by the total link clicks.

eThis value was calculated by dividing the total cost of the ads for both platforms by the number of total enrollees.

fN/A: not applicable.