The key aspect to estimate how much you can earn is the page RPM you can get.
The average I have seen across my sits is around $2. Some niches have lower RPMs (e.g., programming, in my case at least). Some niches have much higher. I had a site about investing in gold that had $12 page RPM on average, if I remember well.
In your case, I believe the number would be higher than $2000 per month if you reach 1 million visitors. I am guessing twice as much at least.
The key aspect to estimate how much you can earn is the page RPM you can get.
The average I have seen across my sits is around $2. Some niches have lower RPMs (e.g., programming, in my case at least). Some niches have much higher. I had a site about investing in gold that had $12 page RPM on average, if I remember well.
In your case, I believe the number would be higher than $2000 per month if you reach 1 million visitors. I am guessing twice as much at least.