Ok, I had to finally create an account to comment on this as well as this thread worried me.
I’m a linux user. I use it 99.9% of the time. I’m also someone who wants to write. I have no prospects or intentions on trying to make a living of writing. Not at this moment yet anyhow. And I have some special situations that make it very hard to use foreign currency (USD for example). So ideally I would just use a simple editor or office suite to write. But I use scrivener now tentatively (the betas) even with some errors and lacks in linux yet because it’s a wonderful program, also I’m choosing scriv mainly both because it’s good and I have a friend (who got me into scrivener) who also tries to write, and with whom I can more easily exchange scrivener documents.
I considered scrivener for linux to be an attempt to port the program to the platform. An attempt that has been hindered mainly by limited staff that has been thoroughly concentrated in releasing a big update for the windows and OS X systems. This exchange makes me feel it’s not so, that the linux port was a compile with winelib just for fun to see if it worked, and since there werent a lot of donations it’s deemed linux users just don’t want to pay for stuff and it’s not worth it…
I’ve not donated, because every cent of mine counts right now (sorry its my reality), and I was expecting, someday, a purchaseable program. I haven’t bought a windows license and used it on wine because I’ve experienced first hand how these things go a few times. I get the license, the thing works on wine, then the new version includes some odd thing (it’s always odd believe me. Normally it’s drm) and the program breaks under wine. I try to contact the makers, and then get a response along the lines of “Tough luck, we don’t support linux, bye”. And then I’m left to lookf for help and hacks and solutions on my own, wich depending on the developer can be differently hard as some actively legally chase and close places where the program is discussed unofitially or worse.
So, what’s the bottomline? I expected to pay for scrivener for linux someday if it comes. I also understand it’s a program for a niche market, and of the niche many writers will not use linux, and those who do might prefer to write in vim or emacs on the command line (I know a couple people who do) or use an open source program, more limited though, than buy scrivener. So if you require a full team of developers to maintain the linu version to par, yes it will probably not be profitable for you to do so. Yet if you achieve an easy to build port that requires not many patches, it might be worth to do it.
What I am not so sure is that it’s a good idea to measure this by the amount of donations.
If you want, see how many demo copies of windows are downloaded against how many copies are bought. Then check how many times the linux versions have been downloaded, if you think linux users don’t like to pay for stuff, lower the purchase percentaje you got from windows some, then apply that to your linxu downloads and project your sales.