While it has been explained, I feel it is important to point out something that I missed for a LONG time when I first started playing. Banks, Markets, Grocers, Wall Street, etc. only increase a city's GOLD and
not its commerce. If you are running your
slider on high (80-100%) then most of the time the boosts from these buildings will be minimal and many times less than ideal. It is important, in my opinion, to build these buildings in cities where they have a big effect (ex. in a city with a shrine or corporation) and not
everywhere like I used to, it is usually a waste of production.