Homework on the company and the industry. I threw out all the unsolicited letters, unless one mentioned....you may have a problem with ABC company (one of our top customers) or.....we believe your top (salesman, COO, CFO, etc) has their resume circulating....or someother piece of "insider" information that would cause me to reread and then f/up myself with a call back. So, do your homework and use a laser vs. a shotgun.

Make your outreach letters as customized as possible and talk about what's in it for them to respond to you. I would keep the I's to the absolute minimum. They're not going to be impressed by who you are and why you're emailing them, rather they will want to know why answering your mail or phone call is beneficial to them.

The only exception here is if you got their email or phone number from a common contact. Then there's a bit more room for a story about yourself for added credibility.