We track who's watched the Pre-recorded, Vimeo Live, YouTube Live, and Replay content you've set up in HeySummit. Check out this article to see how to export that info. Note that we don't track how long someone stayed on a talk page for, so it won't be possible to tell if they watched the whole session.
We can't track who's watched sessions you connected to one of our webinar integration, but not to worry, these stats can be found in your webinar provider account.
With this info, you can get in touch with the attendees outside of HeySummit by importing their email addresses into your email service provider, with a certificate you've created externally.