Visitors/viewers needed to attract advertisers on a live internet video broadcast

I have been thinking of creating a programmed livestream internet video broadcast (like a TV channel on the internet) for quite some time now.
The streaming server would cost me $100/month for up to 25 simultaneous viewers. Obviously, the price increases for more simultaneous viewers.

Can anyone possibly provide an estimate of how many visitors or viewers I would need to attract advertisers and at least break even on the cost?
(Video advertisements would be shown about every 15 minutes during the broadcast.)

The answer is really going to depend on how much value your audience poses and your ability to sell it. There’s sites selling video ads making a $0.30 for every thousand views [CPM based on the CPV] and sites making a $30 CPM. Network run ads will fall on the lower end – how low also depends on the response and demographic targeting, the networks and your optimization of it all.

You can do the math at any level with any combination but the short answer is that you’re going to need to think at a much larger scale than 25 viewers if you plan to work on an ad model.

Of course if you can build something where people pay for access, well then it all changes.