Source: Bigstock

Copywriting is foundational to any sales process. Yet, I've bought dozens of subscription boxes, and few companies get it right. I've also subscribed to and reviewed hundreds of newsletters published by everyone from financial advisors to health care providers to industry trade associations, and few understand it. The biggest mistake I see in ongoing content is that it's 100% "how-to" information. Subscription boxes focus too much on the value of the individual samples that ar...