As you know, Google Penguin actively struggling with low quality links to your site and can penalized your site in search.

What do you think about this?

On the one hand sites that promoted with links from substandard resources (i don't mean spam in this case, just low quality links) quite often penalized in search results.

On the other hand - I can provide many examples of sites in the top promoted by spam comments, spam guest books and no Panda or Penguin does not affect them.