Their loyalty, their top of mind awareness of you, and their memory of your contribution to their experience (that they share with everyone they know) will make a far bigger impression on your wallet than a magnet on their fridge with your name on it. 

An example of my standard disclosure is listed below:Michael King is a licensed real estate agent (license # blah blah blah) with Blah Blah Realty. 500 blah blah street, Leominster, MA 01453. (978) 555-5555.I am ordering car magnets for my investing business.

Kohler Echelon with a half-header, magnetic closure.

But, if you have your newsletters printed, and you mail them, you could include a refrigerator magnet printed with a sports schedule, tips for baby sitters, or a local shopping directory of websites.

I also have car magnets. 

What I also did was get car magnet signs that read just like my bandit signs.

Can you trace any acquisitions back to your signs, people, and car magnets?  

Everyone gets a business card on a magnet that touts "We buy apartments and mobile home parks."

No sure if any does it in your market.. but if you have a specific market or NH that you want to hit.. knocking on 10 doors a day leaving your refrigerator magnet..

Many kids go to magnet schools in the area.