Right now people are just piling up their wishlists and waiting for promos and sales to buy games on their wishlists. People do not want to pay full prices for anything. When people buy anything at full price without any reward or incentive, they would feel they pay too much. So here is a suggestion to encourage people to buy at regular prices:

In addition to promos and sales, GOG should set up a special points system like a mileage program: people earn points when they buy games at full regular prices. The GOG points can be used to discount non-promo games, (i.e., they can use the points to lower the prices of games that are not on sales.) With enough points, people can redeem games for free.

Then we would not have hold off on buying games on our wishlists and wait for promos. We can buy games at discounts during promos but earn no points, or we can buy games at full regular prices and earn GOG points. That would be an incentive for people to buy at regular prices because they would be rewarded with points.

Of course, the GOG points can be gifted or traded. GOG can have "double miles" specials, etc.