i make a Google alert account. i receive mail for activation. i active my alert account but 1 week spend i am not received any alert from Google. what is the reason?
Well, the only reason I can think of is that your keyword is not having much activities. In other words, noone posts anything about your topic.
Your account must not yet have been activated, go back to the mail you received and there you'll find another link where you mail them back and ask for your problem.