Yesterday's outage prompted annoyance that turned into disbelief and then outrage, as Tumblr's nine million users yearned for cat pictures, magical rappers and photos of Kim Jong Il looking at things.

Henry Blodget of Silicon Alley Insider posited at one point that Tumblr was stalling because it had "lost EVERYTHING," a claim which Tumblr President John Maloney shot down as "ridiculous."

Karp writes in a post called "Downtime":

While you might feel like you've gotten used to seeing errors on Tumblr recently, know that this is absolutely unacceptable to our team, and unacceptable for a platform determined to be the best place in the world for your creative expression.

Tumblr caught flak yesterday for crashing after what seemed like a week of intermittent downtime reminiscent of Twitter's frequent fail whale days. The blackouts seemed especially unfair to users considering that Tumblr had just raised a boatload of money.

But that deal hasn't been finalized yet, and the site has gotten to 500 million pageviews a month, Karp said, too much for Tumblr's small team. He added that Tumblr has "nearly quadrupled our engineering team this month alone."

It seems unreasonable to expect so much from a free service, but Web users are tough customers (see Marshall Kirkpatrick's take over at ReadWriteWeb, "Why a Day of Tumblr Down Time Matters to the Entire Web & World"). Fortunately for Tumblr, even 24 hours wasn't enough to make users abandon the service.

ajeffries [at] observer.com | @adrjeffries