Well done! We can also introduce more features into the previous report. We'll use these features to analyze if good customers have anything in common (other than high average order values). Check it out:

WITH GoodCustomers AS (
  SELECT
    C.CustomerID,
    RegistrationDate,
    C.ChannelID,
    AVG(TotalAmount) AS AvgOrderValue
  FROM Customers C
  JOIN Orders O
    ON C.CustomerID = O.CustomerID
  GROUP BY C.CustomerID, RegistrationDate, C.ChannelID
  HAVING AVG(TotalAmount) > 1636
)

SELECT 
  DATEPART(Year, RegistrationDate) AS Year, 
  DATEPART(Week, RegistrationDate) AS Week,
  ChannelID,
  COUNT(*) AS GoodCustomers
FROM GoodCustomers
GROUP BY
  DATEPART(Year, RegistrationDate), 
  DATEPART(Week, RegistrationDate),
  ChannelID
ORDER BY
  DATEPART(Year, RegistrationDate), 
  DATEPART(Week, RegistrationDate);

In the query above, we've added a new customer field in the CTE: the acquisition channel. We used the ChannelId column from the inner query and showed it in the outer query to get additional information about customers.

This way we can check if any channels are particularly good at attracting good customers. If we identify good channels, we can put more marketing efforts into these channels to attract even more good customers.