E-mail generates an immediate response. By providing links within your e-mail, you give potential participants the opportunity to register right then and there. You can see the results of your efforts instantly. If you are ever asked for your password in an unsolicited manner or by someone you do not believe to be a representative of Yahoo!/Hotmail/Facebook/gmail, etc., please do not share your password with them and ask them the reason for asking or contact directly the respective company, as they have a separate department to handle such issues, like Yahoo! s mail abuse department.