This was a great read. I've done a lot of research (and work building campaigns) in the social media space and going "viral" is an interesting subject. The campaigns you're speaking of with Red Bull or any viral video like Gangnam, etc. are just pieces of content that are more viral than others. The important thing to note here is that, in fact, all internet content can be viral to some degree.
It's not as simple as a "viral coefficent" or "k-factor." That's an often misunderstood algorithm for virality. What k-factor tells us is more of an adoption rate or growth/acquisition rate. It's main use is for things like "signups" or app installs, etc. Yup, opt-ins as well (as you go on to talk about).
However, when it comes to the spread of information and content sharing, k-factor or your "viral coefficient" is not what you need to be using to measure how viral that content is. Instead, what you need is a comparison and ranking algorithm (much like ViralityScore.com). For an example here; if we were going from content to users/influencers, we also then have things like Klout, NetBase, Moz, etc. etc. There are many sources to rank influencers (and conversions), but very few to rank content. If you want another example of content ranking, you can check out Unruly's viral video charts (though it's just limited to some YouTube videos and is a pretty basic approach).
So each piece of content across the internet actually has the ability to become viral more easily than you might imagine. The question is then, ok, "how viral?" That's actually the first, most basic, question that people often skip. Without understanding that, you can't really understand viral media - at all. For without knowing that, you also don't know when content ceases to be viral or when it became viral. You don't know where it stands in relation to other content. Therefore, people not measuring and understanding this, are simply unqualified to label anything viral.
This is more problematic than it sounds. Bear with me for a second, I will get back to why your observations were very important. So with a site like say, Mashable, you see stories about what the most viral Instagram pictures were for the week, day, whatever. The truth is, those weren't measured. Someone simply went over and searched for a few images (say with a query of "cat") and took the first five and said, "OK, these are most viral!" Or, they were actually paid to promote certain "cat" content and falsely (or truthfully after people saw the article and went to the content) labeled it as viral. The reality is that the authors had no idea if the content was viral or not. They couldn't prove or measure it.
This brings us back to your article. What's important to note here is what, like you said, $65 million dollars were spent making this viral campaign. Obviously a lot went into the entire operation when you think about the costs involved with sending some dude up to lower orbit. However, it's important to also note that a lot of that money went into PR as well. Perhaps it came a bit easier for them, because sending a guy into space is a little harder to ignore...But for most companies this PR comes with a cost. Like you also noted, advertising can help with this push.
Again, like you said, "true virality" or waiting for it to just happen without any guidance is really rare. I agree, it is! But there is more "organic" virality out there than you may think. It's just a matter of how viral.
If you take the Red bulls and the wrecking balls and the Gangnams out there...You're really only talking about less than 1% of all internet content. So when you think about it, doesn't it make sense that more content is viral? We, as a collective of internet users, have heard about (and share) more than just that. Even this very article is being shared out there and it didn't cost you a cent, right?