QUESTION 1: Top 10 Sellers that used the SponsoredType 'SponsoredProducts' ordered by the number of orders descending.
ANSWER:
WITH sales AS (
-- Top 10 Sellers by sales volume
SELECT s.accountid AS seller_id, s.sales, s.orders
FROM sales AS s
ORDER BY sales DESC
LIMIT 10
)
-- Top 10 sellers that used the 'SponsoredProducts' ad type
SELECT DISTINCT s.seller_id, a.sponsoredtype AS ad_type, s.sales, s.orders
FROM sales AS s
LEFT JOIN advertising AS a
ON s.seller_id = a.accountid
WHERE a.sponsoredtype = 'SponsoredProducts'
ORDER BY s.orders DESC;
/*
NOTE:
This query reveals that only 4 out of the top 10 sellers (by sales volume) used the
'SponsoredProducts' ad type.
*/