With The Motley Fool, a well-known financial advisory services company, having recently predicted that Amazon.com’s ad prices could go up next year, the million-dollar question is, is it still worth investing in Amazon marketing services, assuming that you could soon be looking at a greater investment? More importantly, can’t you simply optimize your listing, and (hope to) sell more? Well, the answer is “Yes” and “No”. Nothing beats the good old Amazon product listing optimization, agreed, but then, Amazon PPC ads come in a close second. They too can be a potential revenue driver, if leveraged well.