Goldmark is the in-game premium currency. Many games have such a feature, and most often this gives certain advantages to players who use it, buying the currency and then being able to use it to make the game easier in various ways. Supremacy 1914 is no different : what makes it unique is the scale that goldmark can be used upon.As a comparison, in the game of World of Tanks, the in-game premium currency is labeled gold. Gold gives a host of benefits : it enables one to buy premium tanks, which earn more credits, enable crew training, and are increasingly competitive vehicles in their own right. It enables premium account, with which one earns more money and experience. It enables one to purchase premium ammunition (which can also be purchased with regular credits in the game, albeit at very expensive prices,), garage slots for more vehicles, free experience, money, to demount equipment, to buy buy permanent camouflage, and retrain crews. All of this is a tremendous bonus, but in a fight between a player using gold and one not using gold in equivalent vehicles, the gold player has no real advantage over the non-gold user, and even in the increasingly overpowered premium tanks, a non-gold player can still win with appropriate experience and skill.
Not so in Supremacy 1914. In Supremacy 1914, the only limits to the benefits of goldmarks is however much money one has available. It is entirely theoretically possible than any player, given enough money, can defeat any possible coalition : he could say, win a battle on a 100 player map against every other player simply by hurrying construction of vast armies of units and taking over the map. Of course, this would be hideously expensive, but just the ability to buy enough units to defeat and hold the surrounding nations can easily make a goldmark using nation dramatically overpowered compared to its rivals.
Hard examples proliferated. In one game, Mcklenberg fought an Italian nation, on a 500 player map. Both were roughly equal in score, but Mcklenberg's action was to take a province near Italy, hurry a factory, hurry 4 battleships, and destroy Italy which had nothing at all that they could do to react. One of the biggest nations in the game was destroyed in only a few dozen hours. Mcklenberg destroyed all of their opposition : the price they told me, had been $500 throughout the game (which doubtless continued to increase, as I left before it finished). In another, Belgium, on day 11, had 225 territories : the next biggest nation had 40. There is no cap on goldmark, and hence if one has the pockets, any enemy can be crushed. Even on smaller scales, the ability to spawn more than a dozen troops instantly in response to an attack removes any strategy involved.
In my opinion, the best way to fix this would be some sort of cap upon how much gold can be spent, perhaps graduated by nation size (with a base level for smaller nations that they can't go beneath). The ability for players to overwhelm their enemies regardless of strategy or skill by cash is one which makes Supremacy 1914 an incredibly unfair and biased game, and until something is done to fix it, one which can never be as good as it otherwise might be.