A closely guarded secret, Google’s mathematical formula that orders websites according to their content quality, has changed, according to a Google blog post Thursday.

This is in response to recent criticism over low-quality websites that rank high on searches but are not useful to the user and instead might be full of advertisements. But many believe the real target is “content farms” — websites that collect content from the day’s most searched terms.

Websites that have been accused of farming content for search engine optimization include AOL and the Huffington Post.

One critic called the Huffington Post’s “story” on the Super Bowl “the greatest example of SEO whoring of all time.” (Judge for yourself here)

Google’s virtual “spiders” constantly scan the internet for content and rank websites according to a list of criteria that many SEO experts have tried to decipher. The list includes relevant content, structure of the website’s coding, and the use of keywords.

The SEO industry, spawning from the search engine market, is believed by some to be a billion dollar industry. Many small businesses look to SEO experts to help sell their product or services online by receiving a high website ranking.

“Our goal is simple: to give people the most relevant answers to their queries as quickly as possible,” according to the Google blog post.

Google, the forefront of online commerce, said that the changes will affect 11.8% of search results on its website, but many webmasters have complained that the changes dramatically dropped their traffic overnight.

“Hey Google, this is not fun anymore – YOU’RE KILLING OUR BUSINESS!” posted one critic on a forum.