What effect did the Zollverein have on the sense of unity inside Germany?

The creation of the Zollverein in 1833 is generally said
to have helped develop a sense of unity among the various states that existed in what is
now Germany.

The Zollverein was essentially a free trade
area that was made up of various states in what is now Germany.  By breaking down the
barriers between these states, the Zollverein helped create a sense that the states were
all part of one greater whole.  In addition, the Zollverein encouraged the idea that the
German states were distinct from Austria.  This gave the German states both a positive
sense of identity (since they were all part of this union with no trade barriers and
with common weights and measures and stuff) and a negative sense of identity (they were
not part of Austria).

By doing these things, the Zollverein
helped to create a sense of unity among the states that would later unify and become
Germany.