Since Google publicly made some statements about the upcoming algorithm / filter updates, lot of SEOs and linkbuilders are concerned about the quality of their link profiles. Since Penguin is part of the Google algorithm, the quality of your incoming links is worth monitoring. In the past two years websites have suffered from either manual penalties or algorithmic influences which in both cases will harm your rankings. I don’t say spamming thousands of links with exact keyword anchor texts doesn’t work anymore, but Google became pretty good (compared to the years before 2012) in detecting unnatural activities based on a website’s link graph. Besides huge numbers of exact matching anchor texts, which are really easy to detect by the way, Google started looking to the quality of links. Article marketing websites, bookmarking websites and blog comments where use on a massive scale to create complete link networks for the purpose of flowing PageRank to specific money generating websites.