what search engine did you use? Google? Google sells/uses all of the search data used.. Amazon is the same way for re-using a search that you performed on their website.
There was an interesting episode of Morgan Spurlock's show on CNN (inside man) Where he wanted to know how easy it was to track someone digitally, then he followed that with how much information is being collected on people digitally. It was pretty eye opening as to how much of one's internet/computer-related life is being recorded. There are several large add companies that basically data mine everything that they can on everyone in the US. Keep in mind, Google makes a LOT of money from their add business they are "kind enough" to let us use their search engine, but as we know... Nothing in life is truly free.. Also, Amazon incentives companies to have links to their site as well.. In todays digital age, it's all about targeted marketing... Just like Richard noticed on the AVS forum, which we know there was some drama there a while back....
In all seriousness, my previous comment was a tongue and cheek comment, but it is somewhat scary as to how much of our lives are being tracked/recorded by marketing companies..
Here is an alternate search engine that does not store/use/sell your searches..https://duckduckgo.com/