Send them invites for your webinars or whitepapers. Send an email regarding it, and wait for their response on it.
? Market your webinars through social media:
As soon as a person register for your webinar, send them a thank you mail and a confirmation mail. Sending this is not only good manners, but will also help get a confirmation from the registrant side.
? Send a Thank you email after registration:
? Choose a relevant topic: