You want other players to collect your resources! Whenever they do, you receive an equal amount!
For example: If your well is showing 50 water ready to be collected, if another player in your city clicks on it, they will receive 50 water and you will receive 50 water too!
This means that your city is a co-operative place! By playing cards to increase your production and having production buildings that are upgraded to high levels, you will encourage your fellow citizens to collect your resources! This way you can passively generate a lot more resources and save on command points!
Hint: Tell your fellow citizens before you play production cards, that way they will know to come look at your suburb and collect your resources! This helps everyone in the city!