I have been purchasing from Amazon since way back when all they sold were books.
Recently my wife and I have been getting into watching their Prime Instant Video by hooking up my laptop via HDMI cable to the TV.  We're trying out alternatives to sticking with cable, you know, kinda like Pink Floyd's lyrics "I got thirteen channels of $hit on the TV to choose from" only we got something like 500.

Amazon Prime Instant video has some pretty good selections of good TV, we have been getting caught up with Downton Abbey and various other BBC/ PBS programs that we never watched before (our local PBS affiliate is worthless even though we have been giving them money for the last 30 years, but I digress) and are discovering how good these series are.
We have been getting into a series called Foyle's War.  This is about a police inspector in a small town on the south east coast of England during WW2.  Excellent  plot and mysteries with excellent characters and cast members.  There are, or were 7 seasons with 4 episodes each available and in my watch list, we have gotten through season 3 and were on the 2nd episode of season 4 when we to watch the 3rd episode and over night it is no longer available!

Here is a copy of my email to Amazon...

I have a selection of numerous seasons of a program called "Foyle's War" in my watch list that up until yesterday (3/21) showed 4 episodes in each season available.  After getting through 2 episodes of a season in the previous week I attempted to proceed to watch episode 3 in that season and it is no longer available!  I noticed that in other seasons of the same series that the number of available episodes had been reduced as well.  Strange how that would change over night?  It's like I could see what I am going to buy, buy it and then what I am buying changes?  Why would your content providers offer such strange privileges?
Who would want to watch just part of a season then proceed to the next season in the series and watch only part of that season?  If that is the way Amazon Prime Instant Video works I will probably not renew my subscription when the time comes.  In addition it will probably begin to steer me away from future Amazon purchases of any kind.

Now I know that this will probably have no effect but it makes me feel better.
Sorry for the long rant,
Gerry