jimbeetle - 3:03 pm on Sep 19, 2013 (gmt 0)
@jimbeetle. I say Penguine 2 because right after the drop I had read an article that said something like "Google released the installment of Penguin 2 today". It just so happened to be on the same day we dropped. Actually, Matt Cutt's blog was flooded by outraged people who saw a drop... right around the time we did. I just believe our drop is related to these changes by Google.
Okay, but just attributing something to what might be coincidence is not the way to analyze a cause.
That said, considering you've been buying SEO services for the site, it's likely -- though not positive -- that it is Penguin-related, as one of the easiest SEO "services" is getting a bunch of spammy backlinks for a site. So, the first step should be to check your backlink profile for any "unnatural" links your SEO companies built for you.