Some of it is marketing but I reclon there is a bit of truth behind it too. These pump products usually rely on ingredients that improve blood flow like citrulline or nitrates which can help the pump during training. That said the biggest factors are still hydration, glycogen levels and training intensity. If you’re training early and fairly fasted you might not get as big a pump as later in the day. Running it with your morning coffee is fine though, plenty of guys do that. I say try it and see if you notice a difference.
I stuffed up first time and didnt weight it just put teaspoon and taste was yeah questionable
But if you put it in shaker with pre workout and shake be careful as it fizzes and could pop lid and you will wear it dont ask how I found this out ha ha