chicagohh - 7:15 pm on Apr 5, 2011 (gmt 0)
I've mentioned things I do. What can an SEO company do to ensure this doesn't happen to their clients? Remember, we don't know what the next target will be - could be any attribute.
Sometimes, nothing. One of my clients (a large publishing company) recently began to have unusual fluctuations in the SERPs. After looking into it a programmer had "heard that keywords were great for SEO" so he decided to do something about it (in large companies it's very hard to have all things relating to the website get checked off by the SEO team).
This programmer added new fields in the website template and encourage people to stuff in their favorite keywords. He then did something similar to this across hundreds of pages - <span style="Google keyword">blah blah</span>. Basically, he would surround the keyword with the span and stuff it in pages.
They are recovering from that misstep, but if Google had turned the dial the wrong direction at that moment it may have been catastrophic.
Sometimes, you just weather the storms...