Thanks a lot for the indepth response!
A/B testing is a great idea, but what's even better is the option to chose A or B on a per domain basis.
For example, let's say I have a domain (A) that receives a lot of query, and another one (B) that...
This is really thoughtful! Will certainly try it out when I get time.
One suggestion: based on my own online data collection experience, the least amount of friction results in more submission.
So the idea is: you'll only show the email address...