Communicating with your old leads helps build your credibility and revive them as your new prospecting leads for your product or services.
Your audience is becoming mobile and sophisticated. They want new content, as well as new ways through which they can stick to the webinar. For this you need to revise your webinar techniques.
It is really difficult to get an audience to be a part of your webinar. You always need to look for a topic from your niche that is trending to be able to capture the attention of a large audience. Do some research and look for customer problems. Be relevant and informative with your webinar topic to encourage more people to attend your webinar.