Roll up your sleeves and do a little research into what makes a successful direct mail campaign tick. The work will be worth the effort. Turns out there’s quite a bit of proven direct mail science you can access to help your cause. First, it’s valuable to know the difference between a housefile address list—a list of donors who have already given to your cause, and a prospecting address list—a generic list of people who have not yet donated. A good prospecting list should pay for itself and eventually grow your housefile list, like a treasured sourdough starter that will feed your organization for years to come. Next, writing a great prospecting letter filled with compelling content is key. You have 20-30 seconds to get your point across. Use snappy headlines, intriguing pull-quotes and an informative P.S. to get your message across. Send a similar letter no more than 3-4 times a year to reinforce your message to maximize results. Read the full article: 

http://www.thefundraisingauthority.com/fundraising-basics/fundraising-by-mail/