Success with prospect letters?
Has anyone had success using cold letters to potential tenants? 
Currently have ~2,500 sq. ft. of space available in a class B professional office building in the midwest. Traffic counts are +10K each day but the space has been vacant for nearly two years and has gotten very little traction with online listings. I'm thinking of sending a prospect letter/ brochure/ flyer to potential tenants in the surrounding area that would fit the profile of the building; attorney, med specialists, insurance etc. Would love some tips on content and to hear if anyone has had success with such a strategy in the past. 
[{"id": "df72ty2", "text": "I have written my own letters and to date have a very high success rate...Even before follow up calls. I've got over 40 different kinds of solicitation letters. It's half letter content half analysis regarding the right targets. PM me and I'll share a few letters and my thought process tomorrow. ", "replies": [{"id": "df7qazp", "text": "Would also be interested in sharing ideas... sending a pm now", "replies": [{"id": "df8l5zh", "text": "I'll follow up tomorrow when I'm back in the office ", "replies": [], "depth": 3}], "depth": 2}], "depth": 1}, {"id": "dfcyzy1", "text": "Less is more, I have had the best luck personally targeting a handful of prospects, rather than sending out a bunch of generic flyers.", "replies": [], "depth": 1}]