This is great. I know these letters are having an impact. (How would I have heard about the site if not for some marketing, anyhow?)
I also think it wouldn't be so bad if the rabbis in a town got such a letter with ONE LITTLE UPGRADE: a little post-it note on it. It would say:
"... AND I AM A MEMBER OF YOUR OWN KEHILLA. WE ARE EVERYWHERE!"
In my view, that's even more of a wake-up call.
I have had my own share of sexual challenges over the years (I'm still a newbie, so my story is out there for introducing myself to everyone - arrgh). In one case, trying to explain to the Rav that "we are everywhere" wasn't working until he found me by accident in some newsletter I didn't even know I was in. He was nice enough to ask if I wanted to talk about it. I did. It was gevaldig.
Having such chats with your rav is not everyone's cup of tea, I know, and having it hoist upon you involuntarily is even less appealing. Even so, getting such a letter with just the generic text might not be as powerful as a yellow sticky saying, "yoo hoo, I'm part of your minyan!"
Just a thought.