The most expensive categories of email lists actually dropped in price from Jan. 2006 to Jan. 2007.

Consumer and B2B email lists, along with newsletter subscriber files, underwent the steepest declines, according to Worldata's Winter 2007 List Price Index, writes Direct Magazine (via MediaBuyerPlanner).

Permission-based B2B email lists continue to be the highest-priced category, though the average price declined $4 to $273/M in Jan. 2007. Consumer email lists saw the highest average drop among any category, down $7 to $160/M.

Attendees/Members and Databases/Masterfiles both had the highest average increases: $5/M.