Last month I decided to buy RunJS license. The price was a bit too high for me, so I contacted them asking if they offer any discounts for users from developing countries. They just gave me a promo code for 20% off without asking any questions.
I offer Purchasing Power discount for my technical ebook if the book landing site detect visitors are from developing countries.<p>It does increase revenue in the sense that I managed to earn money (although lesser) from these customers that I would have never earned otherwise.
We don't, but we have a freemium model. So one option for users wherever they are is to use the free version. Paid versions have support and extra features.<p>We do have a software product, so the marginal cost is close to zero.