Wade Roush just wrote an in-depth article describing the origin story of Optimizely. Here are some snippets:

Simplifying A/B testing software was an idea born on the campaign trail. “I spent the summer of 2007 on leave from Google, sleeping on the floor in the office in Chicago while everyone else was in Iowa,” Siroker recounts. “When I showed up they had a guy doing blogging and a guy doing e-mail, and a ton of people coming to the website. But they didn’t know what they should be looking at. Joe Rospars, the director of new media, thought the biggest opportunity was to tap into that data. We started with one simple experiment on the splash page that generated a substantial increase in e-mail signups, and in the end it meant big dollars for the campaign.”

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Online businesses and Web designers are closer to Optimizely’s sweet spot, and Koomen says the company has found enough users that it’s been profitable (or at least ramen profitable) since before it exited Y Combinator. The startup has raised $1.2 million in angel backing from the usual suspects, including Sam Altman, Paul Buchheit, Ron Conway, Chris Dixon, Steve Huffman, Nils Johnson, Mitch Kapor, Ashton Kutcher, Ariel Poler, Naval Ravikant, Aydin Senkut, Ram Shriram, Joshua Schachter, and Brian Sugar. It’s now got nine employees, all working from the startup’s stylish loft adjacent to San Francisco’s South Park startup haven, and there’s enough revenue coming in the door that the company doesn’t need to think about raising more investment, Koomen says. The startup’s focus right now is in “customer service and retention, learning our sales cycle, and building out the product,” he says.