We provide a free service that helps you setup and deploy load testing instances in your Amazon account. You have to pay for the load testing part of this on the spot instances - hence the (Almost). As an example: if you want to run a load test with 200 m1.small Load Agent Servers hitting your application or site, we can manage them as spot instances and it will cost you about $2.00 for an hour. That should give you enough horsepower to emulate 50,000 users continuously providing load. And we provide you with some pretty real time graphs and reports when you are done (and that part is free).