From the website of a journal where I published an article:
In Springer journals you have the choice of publishing with or without open access. If you choose open access, your article will be freely available to everyone everywhere. In exchange for an open access fee of € 2000 / US $3000 you retain the copyright and your article will carry the Creative Commons License. Please make your choice below.
Hmmm . . . pay $3000 so that an article that I wrote and gave to the journal for free can be accessed by others? Sounds like a good deal to me!