On the Web, there was evidence that the largest search engines Google and Yahoo are interested in their visitors, how relevant were the search results. The Search Engine Watch website has screenshots showing how the Yahoo portal offers to evaluate relevance on a five-point scale.
According to the author of the record, this is not the first time. The search portal was previously seen for similar "acts". Moreover, Google is also interested in its users if they are satisfied with the work of the AdWords contextual advertising system. True, such questions “pop up” very rarely, so only those lucky ones can see them (and answer them).