Facebook Inc. announced today, retailers have increased their use of a particular advertising tool that allows them to send promotions directly to their existing customers. Marketers have been using Facebook's Custom Audiences have increased 75% in the third quarter compared to the the second quarter. This is clearly marketers preparing for the huge holiday season rush. With Christmas around the corner Facebook has been pushing for more retailers to spend more on advertising to its more than 1 billion users. Online sales are expected to increase 15% this year to $82 billion, and Facebook is trying to get as much advertising dollars as possible.