As his extensive suite of benchmarks and product comparisons shows, this elegantly overcomes the problem of diminishing returns that come with adding more read-

As his extensive suite of benchmarks and product comparisons shows, this elegantly overcomes the problem of diminishing returns that come with adding more read-only slaves in a classic master-slave RDBMS replication setup without resorting to extensive use of non-relational solutions such as memcached. Just kidding, he did it cuz it's fun to write cutesy JavaScript hacks that leak memory like hell and turn any machine slower than a Core 2 Duo into a paperweight.