As I wrote a while ago, Amazon was contemplating an increase in Prime Membership cost. It's official. In 7 days, on 3/20, Prime memberships will go up $20 to $99 a year. If you have been contemplating a Prime Membership, you have 7 days to save $20 on your first year. It has been discussed that Prime becomes a habit, leading to much higher spending with Amazon. Amazon is taking a big gamble here with the absolute best customer loyalty program in all of retail. Whether the gamble costs Amazon or not remains to be seen, and we may just never know. Amazon is often vague on earnings calls about specifics; it’s unlikely to be especially forthcoming about this change.
But there is a good chance that this won't affect Amazon much at all. I personally see even the $99 as a complete bargain for the services and savings I get. Between Prime Video, and the Shipping savings, it more than balances. I saved over $600 in shipping costs alone last year with free Shipping with Prime. Take a look at a market comparison. As Slate points out: "Though they don’t have exactly the same libraries, a Netflix subscription alone comes out to about $96 a year. And consider the retail competition: At Walmart, three-five day shipping on small orders costs $6.97, 7 percent of a whole Prime membership."