Well, I am currently prohibited from using it where I work, for some good reasons and some bad ones. The good reasons include things like not having any isolation between users. I work in a regulated industry, and if an SQS task includes sensitive customer data, I cannot ensure it runs only on machines in my VPC, nor can I ensure that the data is encrypted on disk, so I am prohibited from using it. The not-so-good reasons are things like "Amazon hasn't provided a written statement about how long it may take for a task to appear on the queues, so we have to assume that it might take days and any task with an SLA less than 'days' may not use SQS." (What can I say... some of our policy people are irrational.)