Is data about links shared and clicked inside of Gmail used to improve Google search results in any way?

I recently sent an email to a collegue that contained a sample design. The designer has a habit of using random text from other websites as opposed to the usual latin. In this design, he had used a review of a caravan for ironic comedy value. The link was something like http://www.desginportfolio.com/playtime/sample101.html The collegue opened gmail to click the link and I did notice that the text adverts at the top of the email were caravan related - Im assuming the technology was able to read the text from the link and decide on a related contextual advert. I realise that this doent answer the question, but an insight into the technology never the less.