How do city states' gold investment quests work?

I was playing Civilization V Brave New World and a notice popped to the right saying that the city-state of Genoa will appreciate gold investment at the moment (20 turns remaining) and will return 50% profit.
I thought if I give them a huge amount of gold like 3000 gold they will return 4500 to me. After some turns I noticed that I didn't get the big flow of gold. I checked the city-state and noticed the gold investment quest is not there anymore.
How do these gold investment quests work?
Best Answer
Investment quests grant additional influence from donations to the city state (IE, if a 1000 gold donation normally grants 50 influence, you will gain 75 influence if you donate 1000 gold during a public works project quest), there is no direct way to get money back from a city state.
Pictures about "How do city states' gold investment quests work?"



How do you ally with a City-State?
Favor Friendly allies to save money. Do Quests offered by the city-state. Liberate a conquered city-state....How do City-States work in Civ 5?
City-States are small independent political entities introduced in Civilization V, which could be linked in the real world to the small nations of little significance that don't have any ambitions for world domination. In essence, they are single-city civilizations that do not compete against anyone for the victory.How do you increase influence with City-States in Civ 5?
However, kindness, such as gifting units or gold to City-States, completing missions they make, or planting spies in their city, will end up in you gaining influence points. There are five stances a civilization can have with a City-State (in order from worst to best): Permanent War, Angry, Neutral, Friends, or Allies.How do you protect City-States in Civ 5?
You can pledge to protect a City-State. Before the Gods & Kings expansion the game required you to at least be friends with the city state before you are allowed. The mechanic changed for the expansion however, now allowing you to pledge to protect city states immediately.Why are there so few city-states?
More answers regarding how do city states' gold investment quests work?
Answer 2
The idea is something like this: investing in a mercantile city state will help you increase your civ's happiness, and in doing so will allow for greater population growth within your civ, which will in turn allow for you to grow your gold reserves more quickly. I've logged nearly 2000 hours playing the Sid Meiers packages: and this is the best advice I can give you; pull out a piece of paper and document all of the cause and effects of the game! It's great fun if you are of an analytical mindset.
Happy playing!
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Ricardo Esquivel, Maria Orlova, Laura Tancredi, Charles Parker