The term "webcast" derives from its original similarity to a radio or television broadcast. Early usage referred purely to transmission and consumption of streaming audio and video via the World Wide Web. Over time, webcast software vendors have added many of the same functional capabilities found in webinar software, blurring the distinction between the two terms. Webcasts are now likely to allow audience response to polls, text communication with presenters or other audience members, and other two-way communications that complement the consumption of the streamed audio/video content.
Don’t feel you need to do a weekly series. A monthly series works just fine, though twice a month is a nice middle ground. And if your schedule is too busy (and let’s be honest, of course it is…), then use a webinar platform like EverWebinar to host an automated webinar. You won’t even need to be there. Heck, you could be kicking it in Belize with a Pina Colada, watching the sales roll in while your webinar is running without you.