Google Search
Google's homepage includes a button labeled "I'm Feeling Lucky".  When a user clicks on the button the user will be taken directly to the first search result, bypassing the search engine results page.  The thought is that if a user is "feeling lucky", the search engine will return the perfect match the first time without having to page through the search results.  According to a study by Tom Chavez of "Rapt", this feature costs Google $110 million a year as 1% of all searches use this feature and bypass all advertising.