You can make anywhere from 3 to 5k just off youtube views/ads for that size of subscriber base. We don't really do anything that goes viral, so that can go up the more views/viral views you get, but we always considered the youtube ad money to be an added bonus. The actual subscribers are worth nothing, it's the views they give you and non-subscribers give you that you make money from. YT is a marketing channel for us, so we don't really think of it as a large revenue generator. Do not build a business around youtube ad money unless you're only wanting to do videos with the mindset of trying to go viral multiple times and get millions of subscribers.