In a digital channel, the funnel may seem like a simpler process, but acquiring customers (having them land on your website or mobile app) and then having them take a pre-determined action to activating themselves (signing up, buying, downloading) is much more complex.

Acquiring and activating customers online is a two part process and will come with a cost (in most cases). This cost is called the "customer acquisition cost" (CAC). This cost is calculated by adding up all the costs required for the acquisition (ads, press etc. ) divided by the number of customers that actually bought or signed up for your product.

Keeping customers in a digital channel is basically the same as in physical channels. You'll want an active blog keeping them engaged, a great newsletter, contests, meetups, social engagement - again, the reason to keep them is that it's more expensive to acquire new one.

In this scenario, you need to worry about maintaining a low "churn" rate. Churn, or attrition, is the monthly rate of customers that stop using your product/service.

Growing customers for the web/mobile channels is very similar to physical channels. Can you up-sell, cross sell, gain referrals from your existing consumer base. In this part of the funnel, you need to focus on customer lifetime value (LTV). After you've focused on acquiring them, keeping them engaged (low churn rate), you then want to figure out how to get more money and value out of them - your LTV should be higher than the customer acquisition cost (CAC) at the front of the funnel.