The online colossus opened an online pharmacy Tuesday that allows customers to order medication or refills, and have them delivered to the front door in a couple days. Amazon will begin offering commonly prescribed medications Tuesday, including creams, pills, as well as medications that need to stay refrigerated, like insulin. But Prime members who don't have insurance can also buy generic or brand name drugs from Amazon for a discount. Two years ago, it spent $750 million to buy online pharmacy PillPack, which organizes medication in packets by what time and day they need to be taken. Amazon said that PillPack will continue, focusing on shipping medication to people with chronic conditions.