Google requires all sites to adhere to the Google Webmaster Guidelines in order for the site to be ranked prominently in the SERP (search engine results page). The Google Webmaster Guidelines are fairly strict and include design and content guidelines, technical guidelines, and specific site quality guidelines. It also includes a list of techniques that should be avoided at all costs. If a website gets a manual SEO penalty a Google reconsideration request may be needed.
If a site is caught disregarding any of these guidelines it raises a red flag and can result in a penalty from Google. In some cases a webmaster might not have realized that the approach that they were taking was frowned upon or they may have been working with a shady SEO or online marketing firm that got them into a mess.
Google doesn’t always come right out and tell you that your site has been penalized. You will most likely find out when you see that your site is no longer appearing in Google search results or when it’s performing much more poorly than it had been previously. These are several cases in which a website may need to submit a Google reconsideration request.
If you believe that you have been penalized you will need to first figure out why the site has been penalized. Review the Google Webmaster Guidelines thoroughly and compare notes with the actions that you have been taking to promote your website online. Common reasons for a site to be penalized are unnatural links or including low quality or copied or plagiarized content on the site. Once you’ve figured out what you have been doing wrong you will need to take steps to remedy the situation. If you have bad links, do what you can to remove them and work on getting better links. If you have low quality content, write original high quality content.
Once you’ve taken steps to improve the quality of your site and abide by the Google Webmaster Guidelines you can submit a reconsideration request to Google via your Google Webmaster Tools account. Sign into your Google Webmaster Tools account, add and verify the site that you want to be reconsidered, and request reconsideration of your site.
Another reason to submit a Google reconsideration request is if you have recently purchased an existing domain and believe that the previous owner may have violated the Google Webmaster Guidelines. Tell Google that you now own the site and will adhere to the Google Webmaster Guidelines.