A building can only helped once at a time. You need to either collect from it or store and place it to allow others to allow the next person to help it. Helped buildings give a bonus of 1 extra xp and 20% extra income. Of the four building types all but crafting ones can be helped.
Can you please explain how the social hearts work? You have to have them collected for visitors to be able to collect them, right? And why do some buildings give hearts and others don't seem to?
