Table 3.

Engagement and conversion key performance indicators tracked by Trial Promoter.

Metric categories	Measures on Twitter	Measures on Facebook
Volume of messages served	Impressions	Impressions
Social media engagement	Retweets Replies Likes	Shares Comments Likes
Link engagement	Clicks from social media message to clinical trial landing page on Clinical Studies Directory	Clicks from social media message to clinical trial landing page on Clinical Studies Directory
Landing page engagement	Sessions Time spent on page Pageviews per visit	Sessions Time spent on page Pageviews per visit
Contact engagement	Contact form usage on individual clinical trial information page	Contact form usage on individual clinical trial information page