Webinar technology has changed a lot over the last couple of years. It's much easier to use and much more dynamic, yet many presenters haven't made the adjustment to the way things work now. The best example is a simple one, but can make a lot of difference: you don't have to share the PowerPoint application in order to show your presentation.
Back in the day, with most platforms like WebEx and LiveMeeting, you had to open PowerPoint, have it open on your desk, and share the application. Now there is a simpler option: simply upload the file as a PowerPoint or PDF (or almost any document you want to share) file, and it will post in the window for all to see. This is simpler for a number of reasons:
By uploading the document it appears properly in the presentation window. It's properly sized for everyone to read it and, most importantly, it keeps your control panel open.
You can keep your "dashboard" open. This lets you monitor the chat and other functions. It also allows you to use the annotation tools to add color and interest to your presentation.
You save bandwidth. Without getting too technical (which you don't have the patience for and I'm not smart enough to explain properly) when you show the presentation, it uses much less processing power on your computer, and less bandwidth as it shoots out the internet to your audience into their computers. This lessens the chance of screen freeze, lag time, or computer crashes that can ruin your presentation or webmeeting.
So when should you use the "share application" feature?
If animation or built-in video is important to your presentation or meeting. Most platforms don't allow you full access to all the cool features of PowerPoint, and won't allow full access to animations and links if you just share the presentation. For that you'll want to have the application "live".
If you want to make changes to the file while you're working with your audience. One of the great features of a dynamic webmeeting is the ability to brainstorm and create documents in real time. If you're collaborating on a presentation, for example, and you want to make changes in real time you can do so with the application shared and all permissions granted.
When you want to limit interaction and don't plan to share control. When you share the application in most platforms, you have access to the annotation and sharing tools, but they tend to be harder to access. If you don't care about that stuff, and want to focus on the task at hand, go ahead and share the application.
I would be very sure that's what you want to do, though. When you limit interaction and engagement, you run the risk of your audience becoming passive. Share the application, and then go back to the regular screen view.
If you just naturally share the application for simple tasks like PowerPoint, ask yourself if you're doing it out of habit, or because it's going to get you the best possible results. If you've been doing this for a while, you might be surprised at the answer.
By the way, you can find more tips like these in my book, 10 Steps to Successful Virtual Presentations (2011, ASTD Press). You can also learn techniques like this in our workshop Web Presentation Basics (next workshop is November 21 and 23).