In less than two decades, Amazon single-handedly transformed the way we think about online shopping. Before Prime launched in 2005, two-day shipping was virtually unheard of — now more than 100 million people use the service, and they expect the things they order online to arrive at their doorsteps in 48 hours or less. There’s just one problem: Amazon, which has focused on obtaining customers at all costs for decades, seems to be looking for ways to cut down on shipping costs. In some cases, that means weaning Prime users off the near-instantaneous shipping they’ve come to expect. In the beginning, free two-day shipping was Prime’s biggest draw. Memberships were cheap — $79 a year in 2005 and $119 today — and users had the option of paying a small fee to get their orders delivered in just one day. Today, Prime is about much more than package delivery: Users can order everything from groceries to a house cleaner through Amazon. But as Amazon has expanded, the promise of free two-day shipping, the main draw of Prime, has begun to come with a lot of caveats. Read more at Vox.