The graph is pretty flat, which indicates the test is not really putting any stress on your server. The load added does not make much of a difference for improvingtheweb.com. One thing we need to put more effort in, I think, is to communicate these things. What can you learn from a graph, what are the prerequisites for getting good test results (in this case, more load would be a good thing).

I think there is a lot we need to do to explain things better. That is the most difficult part of all.

I think there's also a lot of value in personalized recommendations.

i.e. Load increased with the following stress pattern, which can indicate an improvement is needed in areas A, B, and C.

second that. Maybe something similar to ySlow? http://developer.yahoo.com/yslow