We used an EC2 service. We did manually manage it via our engineers. We also used Knime and looked into Kinesis. 

We are also using Hortonworks, which is now a part of Cloudera.

We didn't use any other products before implementing EMR. Some of our clients have Cloudera distributions, but we prefer EMR. 

No, not really. The reason that we used it at that company - when I got there, that's what they were using. It was because my boss was very big on using those managed services from Amazon because it does give you an additional layer of insurance where, if something goes wrong at the level of the operating system for instance - the patching for the operating system for the nodes in the cluster - that's on Amazon to take care of that. We didn't have to focus on that so we could focus on actually getting the work done.

We used another vendors cloud solution to host our own Hadoop cluster. It wasn't scalable and productive enough,

No solution had been used previously, but we are using it alongside Hortonworks.