I strongly disagree with the suggestion that it's just to pad their profits. The price hasn't increased in years, and yet they have added so many features to the Prime program in that time-and haven't charged more for it. I think that the price increase is LONG overdue. Don't even get me started on the price increases in postage that they have eaten over the years.
I would like to see several tiers though-Prime for shipping without all of the other features, and one that includes the TV streaming for instance.