Does it? Or does it show that a small number of highly technical users are willing to pay more for a different email experience? It's a bit early to judge their impact on the ecosystem, and I'm skeptical they'll capture a significant user base in the way that Gmail did.

People use email because everyone uses email; you're not going to get people to change how they use email entirely. Nobody cares that it's running on SMTP, they care that they can email everyone they know with an email address.