Gratitude Coorelation

I'm making a few VC intros for a founder I rate highly, the replies:

A+: "Many thanks for the intro!"
A: "I appreciate you thinking of us!"
A- "Thanks for sharing the opportunity" (x2)
B: "Please introduce me"
B-: "Happy to speak with them" (x2)
C: "We will have a look"

I wouldn't say the differences are huge, but next time I'll certainly consider prioritizing the 50% who say thanks.

Interestingly, how appreciative the reply is correlates well with the 'tier' of the fund - the A's are all top European VCs.