See here is a query regarding postcards. We have built a list of people who are probably interested in our services, these are basically opt-in addresses. If we mail them then what to expect that the mail response time will be? Anybody any knowledge in this field?
Well if you are using opt-in leads then I will say that wait until 4 weeks atleast.
Now, here is the catch. If you don't receive responses by the end of the 4rth week than you have recreate the mailing pattern from scratch.
Wait for a month and see how many responses are you getting. And also check that whether or not all the addresses are valid as of today.