I don't think the "open core" model is in their best interests. Look at a company like Zenoss, where their OSS version is their biggest competitor. It doesn't make sense for ES to do that.
Now marvel[1] is where they've started monetizing and I'm sure they make a good bit of money from "professional services" teaching companies how to deploy ES at scale. Hopefully they pull it off, as the world needs a good competitor to splunk. ES has the backend tech, but kibana has a loooooong way before it rivals the interface for searching splunk. Here's to hoping!
Marvel is quite interesting. It is a product everyone _could_ build on their own (basically, it is Kibana over their own metrics data), but at that price point, there is no reasonable reason to do so.
I was in a class with the founders a few months ago - for whatever it's worth, they're vehemently opposed to segregating functionality like this.
Their plans are to offer support, and make their bones that way. Elasticsearch is a complex enough product at scale that this would probably be quite lucrative.
ElasticSearch is a sufficiently complex system that can be implemented in a ton of different ways to solve a ton of different problems. I'm sure there are more than enough consulting gigs floating around for them make a good bit of money both on actual consulting and selling additional software packages.
What would be so bad about an enterprise edition? Many companies require extra support and would pay for the enterprise edition and wouldn't even consider the product without this option.
Elastic Search make their money from Enterprise support licenses. There are so many ways of installing it , scaling and optimizing depending on application. Don't forget the training around. You have IBs like Goldman Sachs using it for log analytics. So the services around that are needed and real. I don't think they will need an enterprise version.
Now marvel[1] is where they've started monetizing and I'm sure they make a good bit of money from "professional services" teaching companies how to deploy ES at scale. Hopefully they pull it off, as the world needs a good competitor to splunk. ES has the backend tech, but kibana has a loooooong way before it rivals the interface for searching splunk. Here's to hoping!
[1] http://www.elasticsearch.org/overview/marvel/download/