Use robot.txt or .htaccess to prevent spiders from following unnatural links you’d created.
After 3 years of experimenting with Google authorship – Google has finally decided to end the journey. Google announced that it will no longer be tracking data from content using rel=author markup and will no longer show authorship results in Google Search. This was announced by John Mueller of Google Webmaster Tools in a Google+ … Read more
Does HTTPS have more weight than HTTP? Does this count in the ranking signal? What does Google say about it?