"You were right all along"

There's a hierarchy in the adoption of new techniques and approaches, particularly in the b2b setting:

You were right all along: The thing you were waiting for is here.
All of the cool kids are using this now: Take a look at the folks who are already on board. That topic you didn't care about so much--you need to care about it now.
Well, you were wrong, but don't worry about it, here's some cover: I know you said that this would never work, but it's working. The good news is that you can talk about how your open-mindedness lets you leap forward now.

It's almost impossible to get someone to try something new today if they also have to admit that they were wrong yesterday.