Initially, I did not believe in buying the tool. I felt I could just go to Youtube and learn. This I did. But after 6-8 phone screening /interviews, I got no onsite interview. Then I emailed Don and bought the Job Interview Tools. I desperately read the guide and applied what it advised. I also exchanged some email with Don where he checked my written responses to questions and commented appropriately. Just within 8 weeks of buying this guide, all my phone interviews resulted in onsite interviews. Today, I have 4 jobs offers: 2 Industry jobs and 2 Postdocs and still have 9 onsite interviews lined up.