NEW YORK - The atmosphere at the Direct Marketing Association's  Insert Media Day at the McGraw-Hill conference center March 6 was  positive, with many traditional direct marketing experts speaking to  the medium's increasing importance in a changing media landscape. Keynote speaker Sam Wheeler, director of advertising and partnerships  at Amazon.com, said his company offers 80 million package insert  opportunities annually as well as on-box ad space and online display  ads. While the Seattle-based online retailer is still finessing its  insert program, Mr. Wheeler said he admired the strength in the  industry's business model. You guys are in a really unique position because you're so  accountable, Mr. Wheeler said. You're always working to make sure  that people get paid and that's reassuring. Speakers at Insert Media Day agreed that the accountability of direct  marketing also ap