I have a new client that I picked up just before their site crashed in Google in the fateful December/January updates. The site is clean and they do not engage in Black Hat SEO techniques.
The client owns about three dozen domain names, almost all of which they had pointed to their main site with a combination of 301 and 302 redirects. They insisted that they wanted to keep these domains pointed at the site, so we reconfigured the 302 redirects into 301 redirects to avoid mirror site penalties.
The client also engaged heavily in link buying programs and had over 300,000 links to the site using very focused text links. Before the Google updates, they held top 10 positions for their most important keyword phrases. Since the update, you cannot find the site in G for their most competitive phrases, but they do show up for less competitive terms.
A few months ago they parked the alternate domain names and the client is no longer heavily engaged in buying site-wide links, but the site has not yet recovered.
Someone else told the client that the 301 redirects created the problem and multiple 301 redirects cause a 6 to 9 month penalty. Has anyone ever heard of this? I've been doing SEO work for over seven years and have never seen a properly implemented 301 redirect cause a problem. Also, I have never found any links anywhere that use the alternate domain names and they were never promoted or actively used by the client.
Does anyone have any experience with multiple 301 redirects causing a penalty with G?