Sampling error

I recently received an email from my employer, with a link and a request to fill out a short survey evaluating a new service available to our patients. I had a brief gap between patients, so I clicked and did the six questions. As I hit submit, it occurred to me that the survey seemed familiar. Hmmm. Looking back in my older emails, I found that I had received a similar request from the same group about 2 weeks earlier, with the same link. I contacted the person who had sent the second email.