I like Ansible, but I have to ask: Is $6M a lot for this sort of thing? It sounds like a lot to me for a GUI tool and "REST endpoint", whatever that means in this context. Is there enough of a market to return $6M x10 or whatever it takes to make the investment worthwhile?
p.s.: I know this post could sound like veiled contempt, but I really am just curious and a trifle perplexed.
I have no connection to Ansible or the deal but I think that you are probably forgetting the team that got them to the current state, their future potential and what they can do with 6M.
It doesn't seem to be a overly large round of funding. Look at comparable rounds at Puppet Labs & Opscode (so you'd probably want to look at Bs since the market is more validated now). Similar business models, and they should be valued similarly, too.
p.s.: I know this post could sound like veiled contempt, but I really am just curious and a trifle perplexed.