The Czech devs of Machinarium have published a graphics breaking down the sale of their indie classic "Machinarium". Apart from the 4 millions sales mentioned, it's only about various percentages:
http://www.gamasutra.com/blogs/JakubDvorsky/20160714/277049/Machinarium_Sales_Infographic.php

Spoiler: On the total amount of units sold, GOG ranks up at 2% (while Humble and Steam are at 35% and 26% respectively)

It's interesting to see how units sold per channel disproportionately translate into net revenue per channel.

mmmmm, time for an edit then :o) Yep, it could be nicknamed as an "humble classic" :o)

Gotta love the Amanita Design touch even in infographics :)

The net revenue per channel is certainly interesting. Humble figures are expected, but I'm surprised at the Mac App Store...

Interesting numbers but I'm more curious to see the stats on Samorost 3 since it was released on GOG at the same time as Steam. Also, times have changed. I wonder if they can achieve half of those sales in 5 years time with Samorost 3.

Because Machinarium appeared in Humble Bundle and was more time on sale (with great discount) in Humble Store than on GOG.
Also Aminita hates GOG.

Can't wait for their infographic on Botanicula, a game they gave out for free a day before its GOG debut.

Gotta love these infographics, especially when their creator has such a good taste in graphic design. I belong to the 8% - bought the game directly from the dev's site although I gifted a couple of GOG copies too. 8% units sold directly to 27% net revenue is impressive, especially when you compare it to Steam's 26% to 29%.

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Maybe I miss something, but I got:
GOG 2% of units, 2% of net revenue
Humble 35% of units, 7% of net revenue

Why would any publisher use Humble if they get virtually nothing in terms of net revenue from them? Surely it would be more beneficial for them to release here, make their money then wack it out in bundles?

Some people value quantity over quality, I guess. Maybe they wanted to have impressive numbers, instead of getting a better revenue.

Steam has 26% and developer Jakub Dvorsky says they sold less then 700k on Steam (second post).

GOG has 2%, that means 700.000 / 13 = 50.000 copies (+- 10.000, if GOG has only 1,6% and was rounded up and if "less than 700k" mean only 660.000, for ex).

Machinarium is nr. 172 on the best selling list.

Edit. in fact 2% means about 40.000 copies ( 4 millions * 49% (PC pie) * 2% (GOG)).

Their revenue from Humble is still better than the one from GOG. You don't really think the same amount of people would have gotten Machinarium on Humble if they had to pay full price for it, do you?