Google spam penalties can be automatic or manual. With manual penalties, you’ll probably be informed by way of notification in Google Webmaster Tools. Unfortunately, you may not always know you’ve tripped a spam filter, especially if the penalty is algorithmic. Those penalties are often more challenging to diagnose because they can be keyword specific down to the page level of a website.
Ever wonder how or why your website lost its once favorable rankings in Google? If you want to stay on the good side of Matt Cutts and Google and avoid potentially activating a Google spam filter, never implement any of the these 32 tactics.