To begin with, I would suggest making a list of your target customer segments, if you havent already. Who will use this service to distribute video ? Media agen

To begin with, I would suggest making a list of your target customer segments, if you havent already. Who will use this service to distribute video ? Media agencies, DIY publishers, sports publishers etc. Your service is not targeted to the users who upload videos to Youtube. Once you have this list, figure out what are current solutions available to that segment of users. Then, start your customer acquisition process. Be it google adwords marketing or organic SEO or whatever. If you want to begin with a niche and evolve from there, thats fine too. Identify which target segment is tech savvy and will be easy/cheap to acquire and can easily try out your service. For instance, DIY publishers might be easier to approach and convince in terms of trying out your service. Wedding videographers might be another (just thinking out loud here). Once you start this way, you should get a good feel of what the market needs, how and where you can acquire users etc.