Princeton, N.J.--Impower Inc., a high-tech direct marketing agency with dot-com stock market dreams, has fired more than half of its employees, lost several key business accounts and is expected to file for protection under Chapter 11 of the federal bankruptcy code, it was confirmed Friday. Impower, a 1999 spin-off from American List Council, had raised more than $15 million from such backers as Counsel Corp., Toronto. It spent heavily on equipment and marketing. Mark Zilling, VP of b-to-b markets and brother of Impower CEO Eric Zilling, has left to join MeritDirect, Stamford, Conn. Such clients as Myron Manufacturing and Quill have switched to Merit. Impower had a popular service called eScores, which ranked the quality of opt-in mailing lists but failed to transform that service into breakthrough success.