The SEC defines when an entity can recognize revenue.

Persuasive evidence of an arrangement exists, Delivery has occurred or services have been rendered, The sellers price to the buyer is fixed or determinable, and Collectability is reasonably assured.

The business environment continues to change with new forms of revenue models are invented. (eg: google, facebook, online gaming etc.) etc. What are the implications / challenges of applying revenue recogniztion rules on new forms of busienss ? How will it change the way auditors audit revenue