Hagel, John. <br/><br/>
Net gain :  expanding markets through virtual communities / 
John Hagel III, Arthur G. Armstrong. 
 - Boston :  Harvard Business School Press,  c1997. 
 - xv, 239 p. :  ill. ;  24 cm. 
<br/><br/> Includes index. 
<br/><br/>Includes bibliographical references. 
<br/><br/><label>ISBN: </label>0875847595 (hbk.) 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Internet marketing.<br/>Customer relations.
<br/><br/><label>Subjects--Index Terms: </label>Virtual communities.