Having a compelling value proposition canvas is not enough - there are many reasons a customer might not buy even though you are right about your value proposition.

Even if you have done customer interviews (customer discovery) and you understand the customer job, customer pain and customer gain, and you've even tested your entire business model canvas, their simply may not be a sufficiently compelling reason to buy to overcome the resistance to change, which can include:
- The customer belief that the current solution is good enough
- The cost of change
- The risk of change
- The risk of buying from a startup
- The customer may have bigger problems that are top-of-mind
- There may be people who lose prestige or even their job - and they may try to ensure that your product is not adopted
- There isn't a sufficiently compelling reason be buy to overcome that above concerns.