When you first were in business, I signed up and sent a few letters the first couple of years. I received a response from the company I sent to each time. But I have noticed over time that I am getting zero responses when I send letters. Are companies just ignoring and becoming immune to things sent via planetfeedback now? That's how it appears to me.

FYI, I do authorize forwarding my contact info to the company each time I send a letter.