For years, Google rewarded sites that had inbound links containing keyword-rich anchor text. In fact, it seemed that's exactly what Google wanted.
Google's Penguin update changed that.
If you're still wondering why your rankings plummeted in 2012, this article may provide the answers you're seeking.
Either way, it confirms what SEOs and many webmasters already know: Ranking factors are continually changing. Optimization efforts Google rewards today can become a liability tomorrow.
If organic rankings are an important marketing channel for your firm, make sure someone on your team is keeping watch.