Joins, filters and grouping are a foundation of data analysis. When we applied them to users and purchases we are able to get insights like revenues per country/per age group etc.
Of course we shouldn’t stop there. When looking at users and books we can get a lot of content insights – trends in categories, popular/not popular books etc.
Let’s find what’s the most popular book in the Bindle’s library. In other words – let’s find a book name which is being read by the most amount of users.
Since we need to count users per book it could happen...