The Relationship Between Reads and Writes on Stack Overflow?

On Hanselman.com, I keep everything in memory because it's a read-mostly environment,. Comments come in. But for the most part, it's 90% for 5% reads. On Stack Overflow, 80% of our traffic is anonymous. We have 20% that engage to site somehow, right? And that are effectively writing something. Which doesn't mean we can cache our question show page that heavily.