The world's largest marketing company, Interpublic Group ( IPG) is another name that's sporting a huge earnings discount right now. The $5.3 billion collection of advertising agencies sports of nominal P/E of 18.9, but back cash out of the equation and that number drops to 9.9. Interpublic's portfolio of agencies includes McCann, Draftfcb and Lowe -- names that have considerable brand value in the marketing world. That marketing value translates into premium pricing for IPG's collective services, and it's a major contributor to the firm's double-digit net margins. IPG is also one of a handful of advertising organizations with a global reach, which means that the firm is able to court a category of multinational advertisers that smaller firms can't offer the same services to. As the advertising market continues to convalesce, investors should expect profits to keep creeping higher. Financially, IPG is in solid shape, with a small net cash position on its balance sheet and $2.6 billion in top-line liquidity. Efforts to increase integration of IPG's service portfolio should stair-step the firm's revenues in the next few years as big clients pony up for add-ons.