According to the "2007 List Price Index," provided by Worldata, prices for both B2B and B2C e-mail lists continue to decrease, to roughly $4 per thousand and $7 per thousand, respectively.

"E-mail CPM’s have decreased by as much as $7.00 per thousand in this quarter alone," said Ray Tesi of Worldata. "Due to the rising number of e-mail lists that are coming on to the market and lower-than-average response rates, many list owners are finding it necessary to compete with negotiated CPM’s and off-rate card pricing."

As you would expect, pricing and fluctuations in pricing varied in different list categories.

Permission-based B2B was the highest-priced category, with a January 2007 straight average price of $273 per thousand, a decrease of $4 per thousand over last year. The decrease reflects a growth in the number of B2B e-mail lists available for rental, which gave mailers more choices and created price pressure within the marketplace.

Newsletters were the second-highest-priced category, with a January 2007 straight average price of $172 per thousand, a decrease of $6 per thousand over last year.

In the permission-based B2C category, the January 2007 straight average price was $160 per thousand — and the category exhibited the largest decrease over last year, down $7 per thousand.

Via eMarketer