Many companies adopt a NoSQL database to transparently and inexpensively scale up horizontally by adding hardware instead of vertically increasing processing power on a RDBMS. To quantify how three of the most popular NoSQL databases (Cassandra, Couchbase and MongoDB) scale as more hardware is added to the cluster, Thumbtack Technology conducted a study using the YCSB benchmarking tool. The full results are now available. If your company is considering NoSQL, this study is a must-read.