Matt Cutts has released a new Google Webmaster Video, answering Barry Schwartz (of SER and SEL) from New York's question:
"Was there a key moment in your spam fighting career where you made a mistake that you regret, related to spam?" - Barry Schwartz
Matt Cutts remembers two mistakes that he regrets within his spam fighting career: not taking a strong enough stance against paid links faster, and underestimating the poor user experience of content farms.
Paid Links
Matt Cutts first spam related regret was letting paid links get a little out of hand, around seven years ago.
Cutts says that he realized Google had let paid links go a little too far when he was at a search conference in San Jose. A very well-known SEO told Cutts that paid links were too prevalent for Google to crack down and enforce their position against paid links. Basically, the SEO thought that paid links were beyond Google's control.
Cutts said Google has since taken steps to increase their rhetoric against paid links, have algorithms that target paid links, increased manual penalties, and take spam reports concerning paid links. However, Cutts wishes they'd taken a stronger stance earlier.
That just goes to show that Google isn't afraid to tackle tough issues, and that SEOs aren't always right when they think they know what Google is or is not capable of. The "waking a sleeping giant" analogy comes to mind.
All of that said, paid links certainly still happen within SEO - despite being a risky proposition with potentially serious consequences.
Content Farms
Cutts regrets his initial stance on content farms within his spam fighting career as well.
He relays a story of having to fix a running toilet - Cutts needed information for home repair and found a useful article on one of the content farm's website, after Googling the issue. That initial positive user experience kept him from realizing the seriousness of the issue for several months, despite negative feedback regarding the content farms.
Cutts regrets over-generalizing his experience and using singular anecdotal evidence, instead of listening to the feedback and looking at more pages on the site. As a result, Google was slightly slower at dealing with content farms than Cutts would have liked.
Cutts ends the video saying Google is always looking for good feedback, and that they're always working to improve Google's search.
