Why do you charge in a different way for AppFabric Access Control than you do for AppFabric Service Bus?
Although applications interact with Access Control in a somewhat similar manner to how they interact with the Service Bus, by sending and receiving messages, Access Control has some fundamental differences in the way it is used. Most importantly, those connections are lightweight and short-lived. That means a single Access Control token processing endpoint can handle connections with a great number of external applications that send token requests. Because of these factors, the primary resource usage corresponds directly to the processing of token requests: unpackaging & decrypting tokens, performing claims transformation against rules, repackaging & reencrypting them to be returned to the requestor, and creating & modifying rules. We use the “ACS Transactions” meter to reflect the direct relationship between these transactional operations and resource usage.
