Another online service is http://www.soasta.com which is $1k/hour (cloud-buzzword heavy but slick UI)

Litmus is more about functionality/compatibility testing, unless I'm mistaken, while our service is all about performance testing.

Soasta does essentially the same thing as we do although they are a lot more expensive and aim for larger clients.

Traditionally, load testing has been both difficult and expensive, which is why mostly larger organizations have been doing it. Soasta I think has therefore aimed for this segment while we're betting on a larger, but so far unproven, market among small- and medium sized companies.

Best of luck to you, I think it's a good strategy. I'd be surprised to find any small business that would pay Soasta at those prices. $1k/hour is the kind of money where I would hire someone instead to build a in-house solution via EC2 etc.