A recent study out of Georgetown University and published in The Interdisciplinary Journal of Research on Religion shows that the annual "revenue" of organized religion in the United States is $1.2tn annually. This makes it the 15th largest economy in the world, and worth more than both Apple and Google.
For anyone not wanting to comb through the report, the Guardian did an excellent summary.
There are many questions which arise from this data, including the issues of tax-exempt status for mega-churches and personas, but also just the idea of economizing faith. If the "faith sector" is this large a part of the American economy, what are the implications of this as more and more people identify as non-religiously affiliated? Will the "nones" have a similar socioeconomic force?
The intersection of religion and economics is one which most professional clergy persons aren't trained in. However, this report could add reinforcement to calls for basic economic classes to be included in seminary trainings.