Presumably a hybrid of #1, #2, #3 is most effective - there are audiences that will respond best to each. I assume the targeting data is out there.

Personally, though, I find the handwritten aspect of the letter, and the from a human being part of the text messages, to be the awkward parts. I've never met the folks texting me, yet they know my name and want to convince me of things. Its advertising, it feels pushy. Being channeled through a real human (even if they truly align with the message) doesn't change that. I might agree with the message, but I still don't want it to barge into my day like that.