It may have looked like this in your letterbox this morning: a letter from the energy supplier, a letter from the bank, two direct mail items and an unprinted white envelope. Inside: a voucher for a 15% discount for the online perfumery. You take note of it, put it on the kitchen table and go to work. What you don't realise in the morning is that you are much more likely to redeem this voucher than the other two promotional mailings.
This surprising result has now been revealed by the latest edition of the "Dialogue Mail Study" by Deutsche Post and the Berlin marketing agency "Collaborative Marketing Club". For the survey, 41 online shops sent vouchers to their existing customers in three different formats: as a self-mailer without an envelope, as a maxi postcard and - last but not least - as a classic letter in a white envelope. The result: the promotional letter achieved a 25 per cent higher conversion rate than the other two formats - across all sectors. In addition, the advertising letter also achieved seven per cent higher shopping baskets than postcards and self-mailers.
We can only guess why this is the case. Perhaps it is the curiosity aroused by an envelope without an immediately recognisable sender. Perhaps the higher value that a white envelope radiates. What is certain, however, is that the other two formats also provide advertisers with very pleasing results with a conversion rate of 4.6 per cent.
Print mailings to existing customers are therefore an ideal complement to unaddressed household advertising in the communication of offers - especially as a promotional letter. Another tip from the study: In addition to a customer voucher, enclose a second voucher for friends and family in the envelope. It doesn't cost any extra postage and brings real success: 22 per cent of redemptions came from the referral voucher.