Happy to do so, as noted I have no direct experience at funding open source projects, but I’ve watched folks try to get a revenue stream from software on the Internet (usually without sucess ) for years .
edit: I expect the user number is from repository updates for the parts repository on github (and is thus low, because win7 on 0.9.3b can no longer update due to libgit2). Every time you start Fritzing it checks the repo and I expect github has stats about how many different IP address access the repo.
edit2: I do have one thought on a potential revenue stream although don’t know how to implement it: Get an agreement with the vendors that gain from having Fritzing parts, I know someone asked Adafruit and they said they can’t justify it so far (they have a github repo of Fritzing parts), I have heard Sparkfun gave a one time donation for the Sparkfun parts in core, and they have their own parts repo. This idea came up initially when I did a part of an Avnet IOT development board for someone. If we can convince Avnet, MicroChip, Digikey, Digilent, whoever else makes dev boards that Fritzing is a valuable addition to their dev boards for new users, they have a revenue stream that they could provide funding from. I expect adafruit and sparkfun are too small to be able to afford that, but the bigger distributors have a correspondingly large revenue stream. I suspect much of the Fritzing user base is education (low revenue streams, unlikely to be able to divert any to Fritzing) and makers. The IOT market via the larger distributors are also a possiblilty if someone has the contacts. The part that started this thought is this one:
Another possibility is a parts creation service that charges to create parts (there used to be one, but I believe it no longer exists, likely because the people to make the parts are no longer available). As you have likely seen I like making parts and wouldn’t mind donating the time to support Fritzng (for me at least doing it my self as a business isn’t worth it for tax and paper work hassle reasons, doing it for fun is more attractive .)
Peter