Hello @Gerald McCullough!
Great advice from @Abel Curiel.
My question is: how many leads are you sending to?
There are two things that you should ask yourself that will help you determine your mailing quantity:
1) Your budget
2) Your ability to handle the calls
It might help you to answer these questions if you had an idea on what to expect in respect to the response rates. For reference, here are the average response rates we have seen based on our customer feedback as well as our own mailings throughout the years:
Yellow Letters- average response rate of 8%-9%, all kinds of calls (angry calls, curious calls, tire-kickers, quality calls)
Postcards- average response rate of .5%, mostly quality calls.
Zip Letters- average response rate of 2%, mostly quality calls. (Great for follow ups)
Greeting Cards- average response rate of 2%, mostly quality calls. (Great for follow ups)
(These response rates are the averages we have seen and the actual response rates highly depend on your market and the competition within your market.)
Direct mail tends to work best when you send a campaign of 5-7 different pieces, 4 weeks apart from each other. Follow ups are key as the average person takes 3-5 touches before picking up the phone to respond.
Hope that helps! Feel free to PM me if I can help any further!