In case you haven't heard by now, Google pushed out an update late last week aimed at demoting shady sites that prey on people who have publicly available mugshots, and charge them to have the images removed.
The New York Times published a big investigative report about the practice and Google's response. The Times had Doug Pierce, the founder of SEO company Cogney dig in and study some of the mugshot sites in question. The piece didn't delve too much into the optimization behind the sites, but Pierce himself has since put up a blog post about the topic, which he pointed us to in an email.
Here's an excerpt discussing the sites' backlinks:
I’d sum up all 3 site’s backlink profiles as a combination of: people angry with them, people in support of them (freedom of information ralliers), people using their mugshot photos as sources, and spam generated by the sites themselves (mostly comment spam which seems to have slowed). It’s also interesting that there are some names that these sites specifically build links for. It seems to be a mixture of celebrities, gangsters, and people in the news like Tamerlan Tsarnaev. What they’re doing is trying to rank for “[famous/infamous person's name] + mugshot” which is harder to do than ranking for random Joe Schmoe who got arrested thus link building is necessary.
The most interesting links though come from media coverage of the mugshot sites. By talking about how sites like mugshots.com impairs lives and is a paid unpublishing scam, they often link to the sites in question, passing the news organization’s authority to them and in turn boosting their authority.
He points to links from Gizmodo, Poynter, The New Yorker and SF Weekly, which link to the sites, but don't include nofollow attributes, so they're passing PageRank.
As he notes in the post, as well as in the NYT piece, these sites also cater to "the long click," which essentially equates to time on site. People who click these results from Google probably aren't quickly going back to the results page. They're seeing why the person in question is on a mugshot site, and possibly looking around at other pages on the site, which is a sign of quality content, right?
People are also likely to click on the results simply because they are what they are. If you're searching for someone, and a mugshot result comes up, you're going to click on it. This, as Pierce points out, is a signal of quality itself.
As noted earlier, while Google's update appears to have helped in some cases, it didn't work for the first example the New York Times gave in its piece.
Image: Doug Pierce (Google+)