Every day we use a set of services and tools which are given to us for free! Some of them are really free, and some of them are some luring marketing technique. We are being used to the idea of free as in I give you my data, you give me your service, but beyond this point, there are some unique services which are completely free! And we are happy for these services, so we should contribute to their existence.
I remember one of my professors who said: I can understand if you pirate a software because you are a teenager and cannot afford it, but if you are working, then pay for the things which make your life easier. We are never to poor to donate, and never to rich to wait for a donation.
I am not a fan of Wikipedia considering the way it is administrated, and my love does not go to a system where the ignorance of the many dictates on the truth of the few.