Some call it the kiss of death in SEO. A “Manual Action” by Google is them saying that something you have done has explicitly violated their terms. This was presented to be on day one. Sitting, waiting for me in Webmaster Tools even though the company had hired and SEO company.
Getting rid of a manual action is no easy feat either. You effectively have to play something resembling 21 questions by taking their hints and fix what you think they are upset with and resubmit your site. From there they will look to see if you fixed what they think is wrong, maybe you did, maybe you didn’t, and the process continues.
Luckily, I was able to fix enough on the site that after a few rounds they removed the manual action. Although, I am certain that it plays a role in your rank even after removal. This continued to haunt me well after removal.