Frequent is similar to Regular. Regular is a different concept from Premium. Premium is the opposite of Discount. Discount is related to Sale. 
Drop is a synonym of Lose. Lose is the opposite of Keep. Keep is related to Saving. 
Frequent <--SimilarTo--> Regular <--DistinctFrom--> Premium <--Antonym--> Discount <--RelatedTo--> Sale 
Drop <--Synonym--> Lose <--Antonym--> Keep <--RelatedTo--> Saving 