Many consumers have reservations about online behavioral targeting. By tracking users' online activities, advertisers are able to understand consumers quite well. Advertisers often use technology, such as web bugs and respawning cookies, to maximizing their abilities to track consumers.[60]:60[95] According to a 2011 survey conducted by Harris Interactive, over half of Internet users had a negative impression of online behavioral advertising, and forty percent feared that their personally-identifiable information had been shared with advertisers without their consent.[96][97] Consumers can be especially troubled by advertisers targeting them based on sensitive information, such as financial or health status.[95] Furthermore, some advertisers attach the MAC address of users' devices to their 'demographic profiles' so they can be retargeted (regardless of the accuracy of the profile) even if the user clears their cookies and browsing history.[citation needed] 

Video Marketing Strategy

In February 2011, Google announced the Panda update, which penalizes websites containing content duplicated from other websites and sources. Historically websites have copied content from one another and benefited in search engine rankings by engaging in this practice. However Google implemented a new system which punishes sites whose content is not unique.[35] The 2012 Google Penguin attempted to penalize websites that used manipulative techniques to improve their rankings on the search engine.[36] Although Google Penguin has been presented as an algorithm aimed at fighting web spam, it really focuses on spammy links[37] by gauging the quality of the sites the links are coming from. The 2013 Google Hummingbird update featured an algorithm change designed to improve Google's natural language processing and semantic understanding of web pages. Hummingbird's language processing system falls under the newly recognised term of 'Conversational Search' where the system pays more attention to each word in the query in order to better match the pages to the meaning of the query rather than a few words [38]. With regards to the changes made to search engine optimization, for content publishers and writers, Hummingbird is intended to resolve issues by getting rid of irrelevant content and spam, allowing Google to produce high-quality content and rely on them to be 'trusted' authors.