K-Factor and How to Measure the Impact of a Handwritten Note
At dysrupt we often talk about constructing playbooks for clients that take “the best from the best.” Innovation is an import/export business and what is new in one vertical can be old hat in another.
Enter the idea of K-Factor, a concept originally introduced in the medical field to help measure how quickly a virus spreads.
The easiest way to measure K-Factor is to take the number of users gained via paid acquisition and divide that into the total number of users leveraging the service. If your app bought 10,000 users and it has 15,000 users, then the K-Factor is 1.5.
The benchmark to build around is a K-Factor of 1. Which means:
- Viral = K-Factor > 1
- Not Viral = K-Factor < 1
Now for those already familiar with K-Factor put down your pitchforks! We know there is a ton of nuance to this calculation, but we wanted to provide a basic foundation to help import this idea over to e-commerce. Specifically, how to turn a customer into an evangelical for the business because marketing can be one of the highest cost centers for any business. Increasing the K-Factor of the business can reduce future acquisition costs and overall provide a much healthier foundation for the marketing portfolio.
The question becomes how to build incentives into the post-purchase journey that can help increase the K-Factor of a DTC business. We wanted to offer several ideas to explore as we have seen this trend increase over the last couple of years. Or if you’re an advertiser reading this, we’re also happy to provide 1:1 consulting on more bespoke solutions for your brand!
- For first time purchasers include a note with a handwritten signature from the CEO. (There are many services that offer realistic printing of signatures.) This letter can make a customer feel part of a new community. People like buying products from other people, not companies. To that end, a simple letter can go a tremendous way to humanize the company and drive the mission.
- After the order, give your customers a chance to become your affiliates. This is particularly important for high-ticket DTC companies as increasing the K-Factor even slightly can mean drastic increases in marketing efficiency. Imagine if a mattress company offered a new purchaser a one time $100 incentive if one person purchases a mattress from their unique affiliate link.
- Include a small message to continue the sale. Here is an example from Sparkpod that in exchange for a FREE VIP warranty and DIY Spa E-Book, they unlocked a free communication channel of Facebook messenger. This was then enabled for upselling their other products.

There are a lot of ways to think through ways to extend the sell and increase K-Factor of an eCommerce business. How much does a simple piece of paper with a QR code cost versus the value it may deliver?
There are eCommerce companies that spend $50MM+ a year on social and spend $0 on how to extend the sale and increase their K-Factor. And then there are companies like Apple that make the experience of a purchase so momentous that people collect their boxes.
We hope our readers can find an impactful way to increase K-Factor prior to the Q4 bonanza of Cyber Weekend!
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Thanks to Luke Chesser for sharing their work on Unsplash.