If you want to add some more interactivity during a webcast presentation you can use polling questions. Various webcast software has an option to use polling questions for your audience.
By means of polling questions you can get a sense of what your audience is thinking or test their knowledge and add an interactive element to your presentation. By immediately showing the results after the poll, you can use this to show interest in the perspective of your audience. You do need to test the functionality of the polling questions before your presentation, to avoid disappointment when it doesn’t work.