Among the root beer brands that do not advertise on Facebook and Twitter, which brand has the highest number of purchases?
do not advertise on Facebook and Twitter refers to FacebookPage IS NULL AND Twitter IS NULL; highest number of purchases refers to MAX(COUNT(BrandID));
SELECT T2.BreweryName FROM rootbeer AS T1 INNER JOIN rootbeerbrand AS T2 ON T1.BrandID = T2.BrandID WHERE T2.FacebookPage IS NULL AND T2.Twitter IS NULL GROUP BY T2.BrandID ORDER BY COUNT(T1.BrandID) DESC LIMIT 1