Nano - 8:11 pm on Apr 16, 2011 (gmt 0)
I believe we are only talking about high-quality sites that were affected by the Panda Update.. Not actual low-quality content farms. The low-quality sites were the target here, and they should've been. They are a waste of time for people using search engines.
Most low quality content farms/MFA sites that were affected, (any that weren't affected that should've been?) go far beyond just deceptive ads. They employ several deceptive SEO and monetization strategies. And they approve crappy articles. The only article directories i've found that weren't affected have strict policies about accepting articles.
And, low-quality sites are the sites that people are blocking via the new chrome website block extension. Google blog confirms that in some cases people blocking sites is a factor. I believe they say 84% of sites that are being blocked are affected by the new algo update(s).