- Ubersuggest keyword research tool for search engines. It has been decreasing the free feature set over time, but is still one of the easier keyword tools to use.
- Google Trends not particularly useful when you are trying to research niche spaces, but still a useful exploratory tool
The ethical ads faq claims
Generally, publishers see around $2.00 per 1,000 pageviews (CPM).
CPM is an odd acronym that stands for "cost-per-mille", mille being Latin for "thousand". There's a bunch of related definitions to CPM is marketing lingo, but it's approximately "just" how much money you make per 1000 views of the ad.
Assuming a single ad per page, and assuming the above number is true, and you wanted a "passive income" of $1000 USD per month, that would equate to a view-count of 500,000 page views per month, or almost 17,000 page views a day.