Applied at CMC Groups for sales position

I recently scheduled an interview with CMC Groups for a sales position in Los Angeles. However, I discovered that the role is entirely commission-based, which raised some red flags for me. I wanted to reach out to see if anyone else has had experiences with this company or similar roles. From what I've gathered, many of these sales positions, especially those associated with ATT, are contracted out to third-party marketing companies. They typically involve working in big box retailers like Walmart or Costco, trying to get customers to sign up for services like ATT or Directv. I'm curious if anyone has insights or advice regarding this type of work.