Direct mail?
from:

We've been running petheaven.co.za for 3 years now and while it grows we really feel we struggle to get through to people over email.

We wanted to try something different by sending handwritten letters and postcards with discounts to our existing customers (note it would be in an envelope addressed to them so wouldnt end in junk)

Has anyone tried this or had any success?

Poster :
Courtzz