Junk e-mail or spam is rapidly choking off e-mail as a reliable and efficient means of communication over the Internet. Although the demand for human attention increases rapidly with the volume of information and communication, the supply of attention hardly changes. Markets are a social...

Balancing the needs of information distributors and their audiences has grown harder in the age of the Internet. While the demand for attention continues to increase rapidly with the volume of information and communication, the supply of human attention is relatively fixed. Markets are a social...

Balancing the needs of information distributors and their audiences has grown harder in the age of the Internet. While the demand for attention continues to increase rapidly with the volume of information and communication, the supply of human attention is relatively fixed. Markets are a social...