Presentation of visual materials most often is accomplished through one of two primary methodologies. The web conferencing software may show participants an image of the presenter's computer screen (or desktop). Again, depending upon the product, the software may show the entire visible desktop area or may allow selection of a physical area or application running on the presenter's computer. The second method relies on an upload and conversion process (most commonly consisting of Microsoft PowerPoint files, other Microsoft Office electronic documents, or Adobe PDF documents).
To attract more participants, you can start from some free webinars for certain times. Once you can get webinars well prepared, run webinars interactively and show the great value of your webinar, more and more participants will be willing to pay for your entire webinars and then it's a good chance to create paid webinars to monetise your expertise.