Process Apps play a huge role in helping business leaders see and understand the power of BPM. As many have posted above: getting a business to invest in a platform is hard. From the perspective of the owners of individual business areas, the value of a platform is often only apparent in its ability to deliver solutions that matter them. Providing those solutions as "Process Apps" helps organizations see the possibility of BPM (better processes, faster times to market, happier customers, etc.) in a way that is immediately recognizable within the context of their business.
Business leaders often don't see that what they have is a "BPM" problem. They see that they have a claims problem, or a investigations problem, or a customer service problem. In order to get them to think about taking a BPM approach to the solution, you need to convince them of three things:
That you understand their business. Process Apps put the conversation in their language, so instead of talking about process instances and tasks, you can talk about claims and subrogation. Having a Process App buys credibility with the business persona and often earns us the right to have a BPM conversation.
That BPM can solve their problem. Many people still don't think of customer service as a "BPM" problem. But if you can show them Customer Service solution as a Process App, they can cross that mental barrier. Same for core portions of the business. An insurance provider may not want to trust their claims solutions to a BPM Platform, but when they see a Process App, they see that BPM can be viable...and more effective solution.
That they get the benefits of a COTS solution without the pain. Business buy point solutions because they look like a great option: take the off the shelf stuff, make a few tweaks and *presto* your app is ready go. Unfortunately, most COTS solutions aren't really built with the "few tweaks" in mind, nor do they help organizations deal with the future. Process Apps deliver flexibility and agility, while not forcing the business to give up the "starting point" that they want from a software purchase.