In every industry, there is a right way and a wrong way to get the job done. SEO is no different. A house built with improper building methods will look nice on day one, but over time problems will begin to manifest themselves. The same holds true for search engine optimization tactics.
There are a lot of ways to get results, some of which are fast and easy for SEO companies. In the past, a site could begin outranking competitors simply because it had more of the desired keywords written on the page. As the old saying goes, it only takes one person to ruin it for everyone. Once SEOs realized they could “keyword stuff” a page to rank higher, the battle began.
Google is reactive, not proactive in its efforts. So, when search results began delivering sites with hundreds or thousands of keywords uselessly filling the pages, they reacted. After updating their algorithm, Google began devaluing sites with an unnatural abundance of keywords. Ultimately, it “penalized” the sites for trying to circumvent the rules.