The guys at The Software Bureau prepared a very useful keynote identifying five sources of waste through which we will run briefly:
Pack Design - according to them, up to 34% of postage costs could be saved by optimising the packing to maximise discounts. A very simple and evident example for this is to fold A4-sized letters to send them in DL envelopes instead of unfolded in C4 envelopes.
Data - address data harvested from CRM and online data capture systems often include records with incomplete, missing addresses and misspelled names of addresses. E.g. around 30% of consumers answered in a survey they would not open a mail piece if their name is spelled wrongly.Formatting
Data Quality - similarly, data hygiene can cause a lot of waste due to duplicates, outdated data sets and recipients who formally opted out from mailing. Keeping your mailing list in proper order can be a sisyphus task. You might want to consider the use of an address verification toolwhich can also enrich incomplete data sets to some extend.
Learning - don't forget to build a feedback loop into your campaign in order to improve for the future. Encourage misguided mail to be returned by adding a message on the envelope. Collect returned letters and incorporate such data into your mailing list frequently. Try to measure customer response from a clear call to action in your mailing or by enriching it with QR codes.