Surprised what the Market Samurai guys are suggesting.

[davebrown1975]

This post is deleted!

[AnthonyMangia]

It's certainly possible that this strategy can help you rank well for your target keywords.  It's also a short-sighted strategy that more than likely will cause headaches down the road.  We're seeing Google continue to move in a direction that favors unique, socially engaging content, and there's nothing to suggest that this trend is going to change anytime soon.  Your best bet would be to take the advice of a certain company known for their linkbuilding expertise: http://www.seomoz.org/article/the-professional-guide-to-link-building-2011

Another, less biased, answer is: it depends.  Perhaps your goals are right for a more short-term approach.  Perhaps you have a very high risk tolerance.  It is the opinion of many that SEO is not really an ethical issue, but more of a business decision, and in that vain, the best course of action is whatever is right for your company - including black hat approaches.