Create a presentation you can deliver which is related to that product. The presentation should be helpful and useful, and mostly pure content. If the webinar is going to be an hour long, then you should have at least 45-50 minutes of good, solid content in there before you ever even talk about the product. An exception would be if the entire point of the webinar is how to use that product.
In May 1995, PictureTel announced LiveShare Plus as a general-use data collaboration product for Windows-based personal computers. The software allowed application sharing, user-granted control of a remote PC, shared whiteboard markup, file transfer, and text messaging. List price was given as $249 per computer. PictureTel referenced an agreement with Microsoft in its announcement press release, and a May 26, 1995 memo from Bill Gates to Microsoft executive staff and direct reports said "Our PictureTel screen sharing client allowing Window sharing should work easily across the Internet."