"What Markov chain generation does is give a nice mix between two different ways of generating load, combining the fuzzing of random request generation with the feel of replaying logs. I think of it as a happy medium."
Why do we need a medium? Replaying access logs at a high-velocity gets the job done.
Companies that Pivotal has extensively worked with: Twitter, Square, and Google.
The first two seem, well, obvious. I can count many Pivots that ended up at Twitter over the last 2-3 years. Both companies rely on Ruby/Java and SF's talent pool is practically drained.
A Google acquisition, while far fetched, also makes sense given that Pivotal is stacked with agile/Java broskis. Hard to imagine what the Pivots would work on. Android? Google+?