Ask right is a huge part of it. I'm on the fence about targeting those likely to say yes and approaching those who don't give an indication. Asking those likely to say yes is more efficient but finding those pristine sites with a unique opportunity is good but less easy to locate and arrange. The Asking Right part helps with getting those less likely to say yes to see it your way and say yes. But you'll still receive more nays than yays.
I don't believe in tricking people to say yes. But I do believe you can social engineer the dialogue so as to streamline the process of getting to yes. This means anticipating the resistance and defusing it with an answer before the question is asked. The answer isn't necessarily words you copied and pasted into the email either. It's who the email is coming from, the subject line, authority and trust signals in the body content, etc.
I think that authority and trust signals from the site will help your cause. And that relates back to where Google would like you to be. Previous to Panda, in my opinion, on-page has traditionally been Google's weakness. Post Panda, maybe the changes should be viewed less as a hurdle and more as a door.