Have you noticed? This has basically become GOG's best selling game in their whole library. It is ALWAYS in the top 10.
It's fun because hardcore gamers who aren't catered to anymore can find a niche here. That's why even something as obscure as Panzer General II can sell decently.

it's not a surprise for me. Arcanum is a great game that had bad commercial fate.
Exactly as Planescape Torment.

You know what else is funny? I wouldn't describe Arcanum as "Hardcore." At least, not in any positive sense of the word. It may just be because the game is really, really good. That's why Fallout, Freespace, and Outcast also tend to be on the Bestselling list.

Not surprising at all that it's popular here.
These games that sell well on GOG are the types that make you feel that you're getting your money's worth. I'm not talking about the low GOG prices because I would have payed more than the GOG price in a lot of cases. I'm trying to describe that I admire and appreciate the complexity and attention to detail and intelligent design that the developers demonstrate in games like Arcanum.

I'm not surprised at all. Arcanum is one of those older games, that have gotten more and more favourable buzz among gamers as the time goes on. Just like Deus Ex, System Shock or UFO enemy Unknown (or X-com as it was in US)
I'd have bought Arcanum here, but as fate has it, I all ready have ownd it for years.

ditto, but as fate would have it I couldn't find my disk and wanted to play again, then it was on sale, so I coughed up and bought the copy here...
attempting to play it under linux + wine, but char movements seems to be very ssssslllllooooww
(Ubuntu 10.4 x86-64 + wine 1.2)
anyways it's a funnish RPG... not the best, but one of the better ones of the last decade...

This is crazy, it now frequently beats the high-profile Black Isle RPGs that were just released. Where do all those people who hear about the game come from?

Probably the best selling GOG game ever now.

I picked this up for 3 bucks. Haven't finished it yet, but I have mixed feelings. The gameplay can be extremely unbalanced, especially since I decided to go for guns. In retrospect, I should have invested everything right away to pick up the elephant gun, because every other gun seems like a pea-shooter in comparison. At the same time, magic and melee seem like they'd be more powerful builds regardless.

Still, the story and setting are intriguing enough, and I've gotten the impression that the game would hold up well on replays if I'd want to try out any of a number of very different builds, but I guess with that freedom comes the often frustrating nature of the gameplay.

This. Arcanum didn't actually review that highly on release, with a lot of criticism for the bugs and some uneven balancing (sadly these were likely due to the game being rushed for release). But as time went on people started to see how rewarding it could be if one looked past the faults. Also fans fixed a lot of bugs, and there are even some balancing mods out there for those who want them. To me, Arcanum is one of the quintessential "retro" games that people will play for the first time long after release. There really isn't anything like it being made anymore.

Heard that the multiplayer component didn't work too well, that would have helped. Mainly Co-op of the single player campaign.

Did see an unofficial mod was being worked on to do this.

For me, a big reason as to why I like it is because it's an RPG that isn't high fantasy. While I have nothing against high fantasy, it's been done to death, particularly by RPGs. That alone gives it quite a few kudos in my books.

Troika really mastered the 'little known gem'-genre. All their game we're brilliantly designed, had deep content, were poorly marketed and horribly buggy at release.

It's basically a sequel to the original Fallout (spiritual Sequel) so no...does n't surprise me in the least.

Actually, discounting free games and games that were given free at a certain point (tex 1 and 2 and Jagged Alliance Deadly Games), Arcanum is the 3rd best sold gog ever, acording to the "order by bestselling" in the games catalog. Just after Fallout 1 and 2.

It is fairly impressive, indeed.

I thought about this some more and I think another reason this has sold so well here is that it's one of the only places to buy it. Other popular games like Baldur's Gate were not only more popular at release (i.e. lots of people still have their original boxed copies) but also have been available for sale at other digital distribution sites and even in repackaged retail boxes in some cases. Arcanum is a lot harder to find.

Add to that the fact that, despite its bugs, there really aren't any other games quite like Arcanum, and I think it's not really surprising that it's selling so well here.