On Friday, 8 May 2015 05:43:14 UTC+2, son_of_flubber wrote:
Besides curious pilots and potential glider pilots, we also exclude international glider pilots (many of whom read English).

I disagree.
I'm a South African glider pilot and I had no issue purchasing a one year SSA subscription in order to gain access to the Soaring magazine archives (for a Dick Johnson flight test report). SSA membership is not limited to residents of the USA so even though I don't reside in the USA, I consider it as a donation towards a good cause with spin-off benefits that I receive indirectly.

Example benefit:
By purchasing a SSA subscription I support the soaring community in the USA.. The sport is promoted in the USA and US glider pilots keep purchasing new gliders from Germany. This keeps the manufacturer of my German glider in business which helps with spare parts availability or the option of a new glider.

Free is nice but not everything in life can be free.