As has been pointed out, I was referring to Geocoder's rates. I had the same confusion though. The request for donations certainly makes it seem like they are beneficent, but they are themselves selling the data. Not that that's legally or morally wrong (certainly not) - it's just a different position to be in.
a) Geocoder only charges for their data if you need it without the restrictions of the ODbLicence it's released under (basically attribution, share-alike).
b) giving it away for free would not actually change anything legally. You can still get sued for copyright infringement even if you don't make any money on it.
