So I'm going to set up a comparison; I attached my Halo 3 Montage and the one that a lot of big-name players contributed to (I even managed to find one with the same song). That montage kicks the living shit out of mine. Now, if you were appalled by the time invested in Machinima, the amount of investment in Halo Montages is far more, at least in terms of density. It is fueled by an entire community of people on youtube, and these editors will spend months on this stuff. I'm sure a lot of the SAC majors know how difficult that is, but I had no idea what I was getting myself into. The montage that is not mine, Carnage & Chaos, actually had funding. Real funding. All for a measly 21,000 views on the most popular Halo youtube channel. And there are thousands of these montages. The account that uploaded theirs puts up new montages on a daily basis, and mine barely made the cut for his secondary youtube account; I dropped a good 24 hours into making me and my house-mates montage.
I wish I would have gotten a chance to write an essay about this kind of stuff. There are so many subcultures even within an individual video game. I've had friends who were members of clans in the original Call of Duty up until just recently, as well as one that still participates in a NASCAR 2002 online community. The internet allows so many lasting connections even when a game is outdated, and I love that. The love of a video game is something that people can bond over.
Side note: If you don't understand Halo, just watch the first minute or so of each video and look at the difference in editing. I lose by a lot.