[Lead magnet effectiveness research]: https://www.getresponse.com/blog/best-lead-magnets-study [Customer Value Optimization]: https://www.digitalmarketer.com/blog/customer-value-optimization/ [Updated Digital Marketing Planning Template]: https://www.smartinsights.com/guides/digital-marketing-plan-template/ [Content DNA Book]: https://espirian.co.uk/book/ [Content Shock]: https://businessesgrow.com/2014/01/06/content-shock/