Though it may seem counterintuitive, analytics are an art, not a science.
Each analytics tool works somewhat differently, for instance each analytics tool will filter out traffic it thinks comes from bots, but each decides how to do that differently.
Additionally, many users block tools like Google Analytics for privacy reasons, so they aren't included in Google Analytics data.
So, your analytics will never be the same in each tool. That's not a real problem, because what analytics should be used for is to understand how things are changing directionally. For example, are page-views going up on recent posts about cats? Maybe you should be writing more about cats.
You can learn more about Plausible on their website. If you sign up with Outpost, our group buying power means you get to use Plausible Analytics at a fraction of the cost you would pay on your own.
If you are on the Luna plan or higher, you will also get Analytics reports from Contextly, which provides content recommendations for Ghost. It is also cookie-less, and Contextly reports should be in line with Plausible, but won't be exactly the same. Like with Plausible, Contextly is provided to Outpost clients at a fraction of the price you would pay on your own, using group buying power.
If you are seeing very large discrepancies between other measurement tools and the reports that Outpost or Contextly (Luna and above only), please let us know at email@example.com.