How do I contact ad agencies?

I create really cool kinetic-art videos ( http://www.youtube.com/watch?v=LLRYo4V3H... ) and would like to work more in the lucrative field of advertising and promo videos. However, very few ad agencies actually respond to 'cold' inquiries, and some are downright hostile towards looking at anything that an artist sends their way.

So, does anybody have a REAL clue how to get their attention? Answers from professionals only, please...

It's true that most companies won't respond to a cold inquiry. I would recommend submitting a traditional resume to any ad agencies that you can find, and of course keep an eye on job listings.

Most agencies rely solely on their internal creative resources, and don't generally look outside for creative input. That is, unless they are specifically looking for an expert in a certain field. Perhaps you could create a website that showcases your work and talks about your interest in partnering with ad agencies? A digital resume of sorts? Another way to get your name out there and to build your portfolio is to do some work for local businesses free of charge or for a low fee.

find them online, call reception and ask how you can submit your portfolio for review on future products, they will direct you forward...