People are rarely ready to buy right away. They want to know more about their options, what services fit their specific needs and if the company and its product or services are right for them. This process may not go straight from A to B and is often a long dynamic process going back and forth.
The journey starts with a customer's first recognition of their need and considerations about how this need can be met (sparked by a spot-on campaign, for example) and ends with the decision to make the purchase (or not).
In the B2B market, the customer journey is often much longer than B2C customer journeys as the decision-making process is more complex.