Socialism and communism failed in the past because they were not technically viable as they are becoming today. i think they are the way of the future if we are to continue the advancements in technology and efficiency we have always strived for.
The rest of your post doesn't really jive with this. If i could sum up your post in two sentences, it would be this:
Sentence 1: Technology is pretty awesome, huh?
Sentence 2: Don't you think we can use it to do some socialism?
Yea, technology is pretty awesome but you're largely wrong. It does eliminate man hours but it only divides labor, doesn't destroy it. Let's use your example of movie rental stores being put out of business by NetFlix (and throw RedBox in there too). Someone needs to run NetFlix and employ a lot of people that handle the legal considerations, technical, business, etc. The bigger NetFlix gets, the more people it'll need to hire to keep up with the workload. Also, the bigger it gets and the more people use it, the more the infrastructure needs to be beefed up to handle it. That filters to the communication industry that needs to employ people to lay more wire, etc. But yea, it'll take a smarter, more specially trained person to work at NetFlix or create communication grids than to stock shelves in alphabetical order with BluRays.
So, what you're searching for but just didn't do a good job of articulating really was to correctly identify that the US economy in particular is becoming much more about information than it is manufacturing. As such, you're going to be hired more for what you know and less for what you can do physically.
However, none of this makes the theory of socialism any more viable. Everyone's worked with that one person who doesn't pull his/her weight as much as they should. Whether it be a work group in a class or at your job, whatever. Socialism only makes it easier for that person to get away with it, borderline encouraging them to do little to nothing, and reap even larger rewards for it. The people around that person go "why am i busting my ass for the same reward as that person?" and they stop busting their ass. Soon after, no one is busting their ass and nothing is getting done but people expect to get "what's owed to them." It simply doesn't work.
I would argue that a more technological society would only help expedite the failure.