IceCube Marketing has recently shared an infographic that explains how to use six principles of influence in online marketing. These can be of special interest to authors, as they are aimed specifically at digital sales and come with simple-to-follow ideas for using them:

Icecube Digital Sales Infographic | Istomedia web database and multimedia design - σχεδίαση ιστοσελίδων, βάσεις δεδομένων, πολυμέσα