Unfortunately, it's not something I have answers to. I guess I just look at the success of something like the Micro Python campaign [0] (also a cool project) and wonder if something similar could be achieved.
There are plenty of companies that could benefit from PyPy doing well though. How many python servers do youtube / reddit etc run? With some investment in PyPy they could reduce their on-going costs. Youtube could easily dump $100k into the PyPy project, so what's stopping them? (I suspect the answer in that case is that Google just aren't interested)
I'm in a startup that doesn't have money to invest in PyPy, but if we we had more cash we'd definitely look at putting some into PyPy (though our use case is the hairy NumPy side of things).
I guess in the case of PyPy it's maybe less interesting to individuals but maybe there's some way of reframing it to make it interesting.
In a way, I'm sort of the target market here, because I use python all the time and I haven't donated to PyPy. So why haven't I donated (other than being quite broke because I'm starting a business)?
I think part of it is the urgency. There are 3 specific campaigns you're running [1] to get funding, along with funding for the general project itself. And the campaigns themselves are great - you have good overviews of the issues that you're solving, a realistic approach and a proven track record of being able to execute. But I don't know when those campaigns started and what the cut-off date is. They sort of feel ongoing and it feels like there's no loss in not donating right now. Compare with something like kickstarter, where you have a date by which if there hasn't been enough funding you may end up losing out on something really cool.
Sorry for the rather rambling brain-dump, but maybe there's some useful perspective here.
[0] https://www.kickstarter.com/projects/214379695/micro-python-...
[1] http://pypy.org/tmdonate2.html http://pypy.org/py3donate.html http://pypy.org/numpydonate.html