Okay. This is sort of a 'duh' post. But...get over it. According to AZA's Economic Impact Report released earlier this year:
"Total contribution of AZA-accredited zoos and aquariums to the U.S. economy in 2010 was $16 billion, generating personal earnings totaling $4.7 billion and supporting 142,436 jobs."
This contribution was attributed to both zoo spending (operating outlays and capital improvements) and guest 'before-and-after visit' spending.
For the full report, click AZA Impacts 2011.