What are the Modules/Techniques of Digital Marketing (Inbound Marketing)?

The flywheel is a business model adopted by HubSpot to illustrate the momentum your organization can gain by prioritizing and delivering exceptional customer experience.
You can spin and build momentum in your flywheel by investing in strategies that acquire and retain customers — forces for your flywheel.

On the other hand, anything that slows your flywheel is friction. Often the biggest sources of friction for your customers come in the handoffs between teams, so alignment and communication between teams are key to keeping your flywheel spinning.
When your flywheel is based on the inbound methodology, your marketing, sales, and service functions can add force and eliminate friction throughout the attract, engage, and delight phases. All organizational functions are also responsible for removing friction from your flywheel.

For example, in the attract phase, marketing will likely play the biggest role by doing things like blogging, event marketing, and running paid ads, but your sales team can also add force by engaging in social selling, and your customer service team can add force by making it easier for current customers to make referrals.

Once you attain enough customers and engage and delight them, they can keep your flywheel spinning by promoting your organization and bringing new customers to you. Over time, your flywheel allows you to grow without continually investing in customer acquisition.