The providers are clever. They store as much data as they possibly can, so users can often find what they need to know more quickly. But in addition, the search engines can use those results to place advertisements where they'll be most effective. Sound harmless? It isn't. Experts say this may cause users to miss information that could be relevant to them in the long term. In the end, the searchers are trapped within the bubble of their own interests. The way to break out is to delete cookies regularly or install programs such as "Wipe" or "Sweepie."