I tried that mail shot thing with my cv about 6 years ago. It went to any financial company in Limerick that looked even vaguely suitable for the type of work I am experienced in. It was about 40-50 pieces of mail, and I researched and rang around to get the correct contact name to address each one to. I got eight replies, and one of them even complimented and waxed lyrical about my beautifully worded application letter. Still didn't result in any job offers though! 