Traditional Internet pricing schemes are coming under continual pressure to adapt to, and encourage, a changing mix of Internet applications and consumer usage patterns. Much research effort over the last decade has been focused on developing more efficient and attractive charging schemes. However, none of the proposed models has been widely deployed. This raises questions regarding the inhibiting factors and missing pieces that make pricing the Internet such a challenge. In this paper, we discuss the problems with current Internet pricing schemes, review the history of Internet pricing research over the last ten years, and summarize the key features and motivations of the most significant models. We develop a novel visual approach to comparing and evaluating such schemes using a three-dimensional (3D) metric encompassing technical efficiency, economic efficiency, and social impact. We address and discuss the important factors that have inhibited the deployment of the reviewed models and suggest productive areas of focus for future Internet pricing research.