Rite Aid Corp. — the third-biggest drugstore chain, which recently agreed to buy the Eckerd and Brooks chains as well — has seen its profits rise of late after its introduction of generic versions of drugs such as Zoloft.

Why? Because generic medications carry a higher profit margin for the big chains than brand-name drugs.

Let me break this down for you: Big Pharma already marks up the brand-name drugs so much that there isn’t much left over for the big drugstore chains. Because generic drugs are much less expensive, however, the chains can mark them up substantially. This is particularly true with so much consolidation among chains, meaning reduced competition.

This is yet another reason to consider purchasing medications online, where there is truly a free — and highly competitive — market.