From the newsletter:
We are sorry to announce that beginning today, StockXpert will no longer sell new credits or accept new members. On February 11, 2010, searching and downloading at StockXpert will cease. This will be the end of image sales at StockXpert.
All SXP members have the opportunity to transfer their remaining credits to iStockphoto. iStock offers the highest quality affordable microstock imagery in the industry. Come and see for yourself. SXP credits will be honored 1 for 1 at iStockphoto.