Pardon my rather long text, but I find that topic in particular always interesting again and thought I'd share my piece of the cake to the very crucial question of how to market your product. (Little tip: Look at some of the really small businesses that sell over eBay, Amazon, gaming sites and then also ask yourself why you are willing to spend money to some more than to others.)
No need to ask for pardon, it's a very interesting little text.
However you're missing one of the most important reasons for piracy: The Collector's Bee...
I got cured of that little insects sting decades ago (with games on the commodore C64, long before the PC-game-era started) and found out that when I only look for games/programs I have the time and interest to play to the end, then that's so few that I can pay for them without problems. (OK, it helped that at that time you got real value for originals, they had more posters, books and other stuff in the boxes when purchasing the regular game than today's collector editions have).
However, a few years ago I watched something in the company I was working that still amuses me today - and probably cured a lot of my previous co-workers from the same problem ;-)
It was when "Lord of the Rings, Part one" had just hit the theaters one month ago - and everyone "knew" that all three parts were made together at the same time.
So there was no suspicion when suddenly a DVD with a copy of "LOTR, part 2" was offered for copying. With about 400 people working there, there was not a single day in two continuous months when there was not one case of someone asking around who had a copy of the DVD to copy it for himself/herself.
But after about two months, that suddenly stopped from one day to the other.
What happened? After two months of constant copying that top movie, someone finally found time to view it...
Let's just say that the title was similiar but not identical to "lord of the rings".
It was a movie about extremely poor people...
They were so poor that they were unable to purchase clothing...
Let's just say that the age restrictions on this forum prevent me from telling the true name of the film on that DVD and that several female coworkers turned very red when asked why they wanted a copy of that DVD...
All jokes aside - a lot of people copy games not to play them, but to be able to tell themselves and others "I have them", often without even checking or installing them.
Those are pirated copies that will not cost the developer anymoney, because those people would never have purchased them anyway, but those cases do distort all statistics about piracy.
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Back to the topic:
There also is another reason why independent developers don't put that much into DRM - a lot of times, those games are in constant development and upgrading, and only the people who purchased from the developers have access to all upgrades - pirates usually don't bother to distribute updates after they succeeded with the challenge of cracking and distributing the main program.
So that is another vital strategy for selling games: sell a basic game, but provide new content to official purchasers for free. Doesn't work as good with RM because you need to be able to update the game content in steps, but it's a good strategy for some developers...
And there is another successfull strategy against piracy as well: Give the game a hidden copy protection - one that doesn't stop the game from starting when detecting a hack, but that increases the difficulty or causes game crashes after playing about 30% of the game. Anyone hooked on the game enough to play to that part will consider paying for it to get the rest - and most crackers won't detect that copy protection because they usually don't play the game to that point after cracking it (they'll be looking for the next game to crack, not confirming that the previous game had a hidden copy protection instead of the usual bug to be fixed with the next update)...