Let's look at an example:
Imagine a business selling soap. Up until now, they have been selling in bulk to stores and do some business on Amazon.
Because of increasing prices and competition, they decide they want to add another sales channel, where they sell directly to the consumers of their soap.
If this business comes to us, we look at their business model, find products worth selling to consumers (i.e. products that can be marketed profitably). Based on this and market research, we decide where this business needs to market.
Then, we get to work and build a website. Once that is done, we run marketing to get traffic to the website and sales for the business.