If someone would have bought 6 gold elixirs in 30 min anyway, then making a more convenient 30 min gold elixir probably wouldnt cut into STS profits. But if the inconvenience of having to constantly re-buy gold elixirs pushes some to try plat elixirs, then creating a longer one would cut into their profits. The trick is figuring out which behavior is more likely... Maybe those who buy a lot of gold elix wouldnt have bought a lot of plat to begin with. And once the gold runs out, maybe they would use plat elix to earn more gold