Your website may not have made questionable fashion choices, or overindulged at an office party, still there are things that can come back to haunt you if your SEO practices have not always been above board.
White-Hat SEO is an industry term that refers to optimizing a website using ethical practices. Unethical or Black-Hat tactics attempt to assume an unfair advantage in obtaining superior organic search rankings. For a time, SEO was a free-for-all. Stuff the site full of keywords you want to rank for and boom, you rank page 1. OK, so there may have been a few other aspects, but that really was a top strategy, and it worked.
Google and other search engines have since developed their algorithms to recognize strategies that are trying to game the system. While link farms and keyword stuffing have long gone the way of Betamax tapes and well, the VCR all together, continual updates to search engine algorithms means that what is acceptable is constantly changing.
What this means is that there may be some old SEO hanging around that is dragging your site down. In some cases, something as blatant as a link farm can simply be removed and, fingers crossed, no permanent damage done. In other cases, there is little you can do other than build a bridge over the bad SEO.
True SEO experts are constantly learning. As Google changes what they deem as acceptable practice, the best SEO gurus are already right there with them. Speaking the language of search affords an understanding that allows SEO experts to anticipate many changes before they happen. Still, relevant white-hat SEO practices begin to build a bridge over the SEO of the past but this may take time.
Often this is evident in rankings that are slow to move when all the right strategies are put in motion. The amount of time this takes will vary greatly based on the extent of the damage done from the past. In most cases, it is virtually impossible, or at least impractical to locate all of the bad SEO from the past, and often nothing can be done to repair it other than starting down the straight and narrow.
UPDATE 10/16: Google has announced a new tool that allows webmasters to “disavow” links that are deemed to be spam or malicious in nature. This not only assists in the quest to stamp out bad SEO, it also may be useful to avoid associations with websites that contain questionable content. We want to caution readers that those managing their own websites should be careful with this tool. Unless it is known without a doubt that a link is doing more harm than good for your website, it is best to leave it alone. Disavowing links that are providing SEO value may have a profound negative effect on search engine rankings. Reinstating links is a possibility, though it may take weeks. For most businesses, a drop in rankings for weeks can mean a big difference in the bottom line.