I agree that Ars Technica seems like a very CDN-friendly workload. I'm curious what those features were that you couldn't ship because of the CDN. It's gotta just be ads, right?
No, the opposite actually. When the ad market fell apart we launched a paid subscriber program. It immediately turned us into an app that cared about a smaller number of high value users. Almost everything we wanted to add was for those folks - personalization and collaboration features, mostly.
Ads have never been fun to build around.