I never thought to gauge my turnaround. I simply tell them what I believe they need to hear, and it's up to them to use the tools I give them. I can't control what their brains or hands do beyond that. I've gotten a few to agree that I make valid points. Doesn't mean a complete 180.
I've been able to do this a few times for others, and it's happened to me as well. my favourite time was when i convinced a certain gager to ask his crush out when he was too afraid to before. now theyre in a happy relationship =]
I don't know how many I have? I've had a few people say I have though. I haven't had my entire beliefs changed really maybe @AleDeEurope changed mine on feminism. But that's about it besides maybe my perspective changing a few times?