The Internet and social networking leaks are one of the issues facing traditional advertising. Video and print ads are often leaked to the world via the Internet earlier than they are scheduled to premiere. Social networking sites allow those leaks to go viral, and be seen by many users more quickly. The time difference is also a problem facing traditional advertisers. When social events occur and are broadcast on television, there is often a time delay between airings on the east coast and west coast of the United States. Social networking sites have become a hub of comment and interaction concerning the event. This allows individuals watching the event on the west coast (time-delayed) to know the outcome before it airs. The 2011 Grammy Awards highlighted this problem. Viewers on the west coast learned who won different awards based on comments made on social networking sites by individuals watching live on the east coast. Since viewers knew who won already, many tuned out and ratings were lower. All the advertisement and promotion put into the event was lost because viewers didn't have a reason to watch.[according to whom?]
When would this be useful? If your site has a blog with public commenting turned on, links within those comments could pass your reputation to pages that you may not be comfortable vouching for. Blog comment areas on pages are highly susceptible to comment spam. Nofollowing these user-added links ensures that you're not giving your page's hard-earned reputation to a spammy site.
Social networking sites such as Facebook, Instagram, Twitter, MySpace etc. have all influenced the buzz of word of mouth marketing. In 1999, Misner said that word-of mouth marketing is, "the world's most effective, yet least understood marketing strategy" (Trusov, Bucklin, & Pauwels, 2009, p. 3). Through the influence of opinion leaders, the increased online "buzz" of "word-of-mouth" marketing that a product, service or companies are experiencing is due to the rise in use of social media and smartphones. Businesses and marketers have noticed that, "a persons behaviour is influenced by many small groups" (Kotler, Burton, Deans, Brown, & Armstrong, 2013, p. 189). These small groups rotate around social networking accounts that are run by influential people (opinion leaders or "thought leaders") who have followers of groups. The types of groups (followers) are called: reference groups (people who know each other either face-to-face or have an indirect influence on a persons attitude or behaviour); membership groups (a person has a direct influence on a person's attitude or behaviour); and aspirational groups (groups which an individual wishes to belong to). https://www.facebook.com/Liberty-Marketing-3011004768971837/