A trademark for the term WEBinar (first three letters capitalized) was registered in 1998 by Eric R. Korb (Serial Number 75478683, USPTO) and was reassigned to InterCall. The trademark registration was cancelled in 2007. Learn.com filed a claim for the term "webinar" without regard to font or style in 2006 (Serial Number 78952304, USPTO). That trademark claim was abandoned in 2007 and no subsequent filing has been made.
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.
You’re already a big winner when you’re in front of your webinar audience. Participants were interested enough in your content to register, hold space on their calendar, then show up attentively to your webinar. They have self-qualified themselves as being in the market for the type of product or service you offer, and think you’re the God of SEO (or whatever your schpeel is on).
So instead of meeting with prospects one-on-one, and making dozens of presentations, a better option is to schedule a Webinar for each Wednesday night for example. Just invite your prospects and tell your team members to invite their prospects to the Webinar too. This way, you, as the best presenter gives the best live presentation, and answers questions. Then each person takes over, and talks to their own prospects and directs them to their web sites to sign them up or make the sale. It’s been done for years, and some of the top recruiters benefit greatly from online Webinars.