I am looking to create a new video-conferencing technology business specifically for established business owners to discuss growth strategies with highly experienced business coaches. I have already identified a live video-conferencing business with whom I could potentially partner - they're similar to Periscope. I am feeling overwhelmed in what to do next and how I should test the market, pick a niche and go about building the product. Please advice.
You don't need much to get an MVP together. Check out SimpleWebRTC for a free, open source video conferencing solution.
I just built a live video platform using a variation of that software (the next generation, Otalk, which is more complex) and found it really simple to get things breathing.
Once you have a prototype, just get people using it. See if someone will pay for it. Keep asking. Run targeted ad campaigns where your target market exists.
You don't have to start with a well-defined niche; see if a group buys in, and your niche may identify itself.
I have a lot of experience with both realtime video and validating/building/marketing new products and services. I'd be happy to offer some insight if you're interested.