Other Ways To Get Feedback?

Everyone that uses my website, I've personally e-mailed them asking for their feedback and will pay them $10.00 for their time via PayPal or Venmo. It's a very short e-mail. But out of the 150ish that I sent, 0 responded. I've also tried without mentioning paying them and also no feedback. Should not be going to spam because they had to activate their e-mail. What are my other options?