You can't easily value Yellow on fundamentals. They have a declining cash cow business. The dividend probably cannot be sustained more than 18 months. Until they have a new growth business emerge you cannot put a growth premium on them. Until their declining business stabilizes, you cannot really evaluate them on historical cash flow metrics.
I think they should do a full on assault on Groupon's market. Yellow has the necessary sales staff to make that business scale rapidly. What's more, they can make unique selling appeals to potential customers like "Buy three promotions with us and we will give you free yellow page advertising." Groupon cannot compete with that.