The Backstory
Posts like this with charts that display EMD (Exact Match Domains) and PMD (Partial Match Domains) declining rapidly have been taken as reliable evidence by many and create a lot of fear-mongering. Do not assume what they say means causation. It is simply correlation.
We have seen EMDs with .us TLDs ranking well. PMDs rank well too. So why does the correlation data show it is declining? Has Google manually targeted these? Not quite.
Data Source
Look at the data source for the EMD and PMD analysis. They are using terms like “appliance parts” and showing a .com and .us dropped off. While “appliance parts” sounds like a big nice keyword, it’s not specific to what people are looking for. As we describe in the keyword research section, you are usually targeting something very specific that people are looking for near the end of the buying process, like the brand of appliance and the exact part needed. Even assuming that “appliance parts” is the target keyword, PMDs still rank.
It’s funny how “they” (in this case, Moz) will stretch data to make a news story. At the time of this writing, #4, #9, and #10 all have “applianceparts” in the domain. 30% of the top 10 is a PMD. That doesn’t make a good news story for them.
EMDs
Most generic, big volume EMDs were taken up by domain resellers…so there weren’t many to begin with. The remaining EMDs were used and abused by SEOs and big companies. Some were spammed to death. Some are just redirects. How many are actually left to use in 2013? Very few. This is why the charts are showing a decline. Now factor in Panda and Penguin. Even if the content was fine, Penguin is a real challenge for EMDs. Most of these sites use their keyword as their brand, and never bothered to build related anchor texts to expand the link profile.
PMDs
Creativity allows for PMDs to never be in short supply. We buy PMDs regularly. They work extremely well, even for homepage rankings. Most are spammed and burned to the ground. Charts showing declines aren’t really accurate.
Big Picture
Don’t avoid domains because someone can show correlations of EMDs and PMDs declining. Just keep in mind the difficulty of anchor texts with these domains, and that deep linking almost never happens (you want to make it happen to help diversity and push the site up). Deep linking isn’t required, but is a best practice.
If you had an EMD or PMD penalized and are trying to recover it, don’t discard it as Google manually attacking domains. Fix it just like any other Panda and Penguin issue.